Human soluble CD146, preparation and uses thereof

ABSTRACT

The present invention relates to compositions and methods for modulating angiogenesis in vivo, ex vivo or in vitro. More particularly, the invention relates to a soluble CD 146 protein usable in the context of human therapy, as well as to corresponding antibodies. Particular forms of CD 146, herein described, may be used to mobilize, in vivo or ex vivo, both mature and immature endothelial cells, as well as to increase their influence on angiogenesis. The invention also relates to compositions comprising such compounds, particularly pharmaceutical or diagnostic compositions, including kits and the like, as well as methods of therapy or diagnosis using said compounds, compositions and cells.

CROSS-REFERENCE TO RELATED APPLICATION

This application is the U.S. national stage application of InternationalPatent Application No. PCT/EP2010/051080, filed Jan. 29, 2010.

FIELD OF THE INVENTION

The present invention relates to compositions and methods for modulatingangiogenesis in vivo, ex vivo or in vitro.

More particularly, the invention relates to soluble CD146 proteinsusable in the context of human therapy, as well as to correspondingantibodies. Particular forms of CD146, herein described, may be used tomobilize, in vivo or ex vivo, both mature and immature endothelialcells, as well as to increase their influence on angiogenesis. They canfurther be used to prepare compositions, in particular pharmaceutical,diagnostic or cosmetic compositions, and corresponding kits.

The invention further relates to methods of therapy or diagnosis, and tocosmetic treatments, using the previously mentioned compounds,compositions and cells.

BACKGROUND OF THE INVENTION

The formation of new blood vessels either from differentiatingendothelial cells during embryonic development (vasculogenesis) or frompre-existing vessels during adult life (angiogenesis) is an essentialfeature of organ development, reproduction, and wound healing in higherorganisms.

Therapeutic angiogenesis is an effective means to treat patientssuffering from a disease or a disorder leading to tissue ischemia.

Treatment of ischemia, using non-surgical therapy, has become possiblewith the discovery of angiogenic factors favouring formation of newblood vessels. Several candidate angiogenic factors have been describedso far which were the subject of clinical trials.

Enthusiasm has however been hampered by series of negative clinicaloutcomes. Regarding VEGF for example, despite the potent angiogeniceffects of this factor, its expression did not efficiently improvemuscle blood flow in patients. This was explained by the formation ofleaky vascular lacunae and arteriovenous shunts interfering with thedownstream microcirculation.

Endothelial progenitor cells (EPCs) have been identified in adult humanperipheral blood, in bone marrow and in cord blood (Asahara T, MuroharaT, Sullivan A, Silver M, van der Zee R, Li T,Witzenbichler B, SchattemanG, Isner J M. Isolation of putative progenitor endothelial cells forangiogenesis. Science. 1997 275:964-7). Circulating EPCs participate inpostnatal neovascularization after mobilization from the bone marrow.Transplantation of culture-expanded EPCs, obtained either from blood orfrom autologous bone marrow mononuclear cells, was found to be able toaugment ischemia-induced neovascularization in vivo.

The use of cultured cells as a therapeutic approach in patients ishowever considerably limited by the small proportion of EPCs in theperipheral blood, the necessity of harvesting a large amount of bonemarrow to isolate a sufficient number of EPCs, and the heterogeneity ofthe recovered EPCs.

Despite their drawbacks, the use of angiogenic growth factors thusremains to date the primary strategy of therapeutic angiogenesis for thetreatment of patients, such as patients presenting with severeperipheral arterial disease (also called peripheral vascular disease) orischemic heart disease.

CD146, also known as MCAM, MUC18, or Mel-CAM, is a component of theendothelial junction which belongs to the immunoglobulin superfamily(Bardin N, Anfosso F, Massé J M, Cramer E, Sabatier F, Le Bivic A,Sampol J, Dignat-George F. Identification of CD146 as a component of theendothelial junction involved in the control of cell-cell cohesion.Blood. 2001; 98:3677-84). As a member of such a family, it consists infive Ig domains, a transmembrane domain, and a cytoplasmic region.

CD146 is mainly known to occur in two distinct forms differing by thelength of their cytoplasmic domain: a long isoform (herein identified as“long CD146”) and a short isoform (herein identified as “short CD146”),both present in the membrane of cells, mainly endothelial cells.

CD146 is involved in the control of cell and tissue architecture, asdemonstrated by the regulation of its expression during endotheliummonolayer formation, its involvement in the control of paracellularpermeability (Bardin N, Anfosso F, Massé J M, Cramer E, Sabatier F, LeBivic A, Sampol J,Dignat-George F. Identification of CD146 as acomponent of the endothelial junction involved in the control ofcell-cell cohesion. Blood. 2001; 98:3677-84) and its colocalization withthe actin cytoskeleton (Anfosso F, Bardin N, Vivier E, Sabatier F,Sampol J, Dignat-George F. Outside-in signaling pathway linked to CD146engagement in human endothelial cells. J Biol Chem. 2001; 276:1564-9).

Membranous CD146 has been reported to promote tumor growth,angiogenesis, and metastasis in human melanoma. Membranous CD146expression levels and distribution are closely associated with tumorprogression and onset of metastasis in human malignant melanoma.Anti-membranous CD146 antibodies have been described as capable ofsignificantly inhibiting the growth and metastasic properties of humanmelanoma cells in nude mice (Mills L, Tellez C, Huang S, Baker C,McCarty M, Green L, Gudas J M, Feng X, Bar-Eli M. Fully human antibodiesto MCAM/MUC18 inhibit tumor growth and metastasis of human melanoma.Cancer Res. 2002; 62:5106-14.). Membranous CD146 has been shown todisplay angiogenic properties, both in an in vitro model of humanumbilical vein endothelial cells (HUVEC) (Kang Y, Wang F, Feng J, YangD, Yang X, Yan X. Knockdown of CD146 reduces the migration andproliferation of human endothelial cells. Cell Res. 2006; 16(3):313-8)and in in vivo models of chicken chorioallantoic membrane (CAM) assaysand tumor growth in mice (Yan X, Lin Y, Yang D, Shen Y, Yuan M, Zhang Z,Li P, Xia H, Li L, Luo D, Liu Q, Mann K, Bader B L. A novel anti-CD146monoclonal antibody, AA98, inhibits angiogenesis and tumor growth Blood.2003;102:184-91). mAb AA98 has been shown by Yan et al. to display aremarkably restricted immunoreactivity against intratumoral vasculaturecompared with blood vessels of normal tissues.

Finally, inventors recently showed that CD146 was involved in theregulation of monocytes transendothelial migration (CD146 and itssoluble form regulate monocytes transendothelial migration.Arteriosclerosis, thrombosis and Vascular Biology, 2009; 29: 746-53).

Different localisations and functional differences have been identifiedin the literature for the two membranous isoforms of chicken CD146. Inone study, authors analyzed chicken CD146 targeting in polarizedepithelial Madin-Darby canine kidney (MDCK) cells using CD146-GFPchimeras, to identify the respective role of each isoform. They showedby confocal microscopy that short CD146 and long CD146 were addressed tothe apical and basolateral membranes, respectively (Guezguez B, VigneronP, Alais S, Jaffredo T, Gavard J, Mège R M, Dunon D. A dileucine motiftargets MCAM-1 cell adhesion molecule to the basolateral membrane inMDCK cells. FEBS Lett. 2006; 580:3649-56). In another study, the samegroup showed that long CD146 promoted rolling via microvilli inductionin lymphocytes and displayed adhesion receptor activity, suggesting itsinvolvement in the recruitment of activated T cells to inflammationsites (Guezguez B, Vigneron P, Lamerant N, Kieda C, Jaffredo T, Dunon D.Dual role of melanoma cell adhesion molecule (MCAM)/CD146 in lymphocyteendothelium interaction: MCAM/CD146 promotes rolling via microvilliinduction in lymphocyte and is an endothelial adhesion receptor. JImmunol. 2007; 179:6673-85).

The existence of a soluble form of CD146 has been discovered initiallyfrom a western blot and its possible role as a competitive inhibitor ofthe CD146 membrane-bound form has been suggested (Bardin N, Francès V,Combes V, Sampol J, Dignat-George F. CD146: biosynthesis and productionof a soluble form in human cultured endothelial cells. FEBS Lett. 1998;421:12-4).

However, until now, the soluble form has not been structurally orfunctionally characterized. A breakthrough results from the inventors'discovery that biologically active forms of human CD146 exist not onlyas membrane-bound forms but also as a soluble form present in the humanserum. Inventors first suggested that changes in sCD146 levels may berelated to physiopathological conditions associated with alteration inendothelial barrier integrity such as permeability, leukocytetransmigration or angiogenesis (N. Bardin, F. Anfosso, V. Combes, J.Nedelec, I. Besson-Faure, P. Brunet, V. Moal, J. Sampol, and F.Dignat-George. Soluble CD146, a junctional endothelial adhesionmolecule, is increased in vascular disorders, Workshop K endothelialcells; DK, vol. 55, no. SUPPL. 01, 1 Jan. 2000, page 63, ISSN:0340-6245) and then described increased levels of sCD146 in the plasmaof patients with chronic renal failure (Bardin N, Moal V, Anfosso F,Daniel L, Brunet P, Sampol J, Dignat-George F. Soluble CD146, a novelendothelial marker, is increased in physiopathological settings linkedto endothelial junctional alteration, Thromb Haemost. 2003; 90:915-20).Inventors now herein describe, for the first time, the structure of saidsoluble forms and demonstrate (see in particular in vivo experimentalresults herein provided) the therapeutic properties of the human solubleCD146, in particular the angiogenic properties thereof, in contradictionwith the art suggestions and in particular with previous observationsfrom Wu Guang-JER et al. (see Wu Guang-JER et al.: “Soluble METCAM/MUC18 blocks angiogenesis during the in vivo tumor formation of humanprostate cancer LNCaP cells.” Proceedings of the American Associationfor cancer research annual meetings, vol. 47, April 2006, page 59 n &97^(TH) annual meeting of the AACR; Washington DC, USA, Apr. 01-05,2006, ISSN: 0197-016X).

In the literature, different soluble receptors, as soluble EphB4 orsoluble Notch1, have been shown to act as endogenous inhibitors ofangiogenesis, acting as traps for their ligand. This is also the casefor the soluble form of VEGFR2 which blocks the angiogenic effect ofVEGF (Holash J, Davis S, Papadopoulos N, et al. VEGF-Trap: a VEGFblocker with potent antitumor effects. Proc Natl Acad Sci U S A. 2002;99: 11393-8.). In contrast, other soluble molecules have been shown toact as activators of angiogenesis, such as the soluble N-cadherinfragment (Derycke L, Morbidelli L, Ziche M, et al. Soluble N-cadherinfragment promotes angiogenesis. Clin Exp Metastasis. 2006; 23: 187-201)or the soluble CD40 ligand (Melter M, Reinders M E, Sho M, et al.Ligation of CD40 induces the expression of vascular endothelial growthfactor by endothelial cells and monocytes and promotes angiogenesis invivo. Blood. 2000; 96: 3801-8.). The reason for the observed oppositeeffects of soluble molecules, inhibitor or activator, is unknown but mayresult from distinct signalling pathways. Thus, one can hypothesize thatsoluble forms of receptor molecules may trap the ligand and inhibit theeffect. In contrast, other soluble molecules, such as soluble CD146,result from a membrane protein shedding, and could serve as a ligandthat activates its receptor.

Inventors in particular herein provide new tools, using the soluble formof CD146, improving the treatment of tissue ischemia while reducingdeleterious side effects observed with classically used therapies. Theyherein demonstrate that the soluble form of CD146 fulfills key functionsin the neovascularisation process.

Inventors herein characterize the human soluble form of CD146 (hereinidentified as “soluble CD146”) and identify amino acid sequences thereofusable in the context of a treatment. Inventors in particular describeits advantageous chemotactic and angiogenic effects on endothelialcells, in particular on endothelial progenitor cells (EPC). The humansoluble form of CD146 is able to promote a therapeutic vasculogenesisand/or angiogenesis in a mammal subject, in particular in a humansubject.

Other advantages of the products and compositions herein described arefurther indicated below.

SUMMARY OF THE INVENTION

Inventors herein demonstrate for the first time that human soluble CD146induces the migration ability or mobilisation (chemotactic activity) andactivation of endothelial cells, in particular endothelial progenitorcells, of smooth muscle cells and of hematopoietic cells, and that thismolecule is able to promote vasculogenesis and/or angiogenesis in vivo.This molecule which may be administered either alone or in combinationwith another angiogenic factor and/or with a mature or immatureendothelial cell, is an advantageous tool for therapeutic angiogenesisin patients presenting with tissue ischemia or at risk of developingsuch a tissue ischemia.

The present invention in particular provides a novel protein, the humansoluble CD146, herein identified as “soluble CD146”. This protein isnaturally present in the human serum and biologically active formsthereof have been isolated by inventors and are herein provided.

In one aspect, the invention describes an isolated human soluble CD146protein containing about 558 amino acids, preferably about 552 to about558 amino acids, even more preferably 557, 556, 555, 554, 553 or 552amino acids.

In a particular embodiment, the invention provides a human soluble CD146protein usable in the context of a mammal treatment, in particular ahuman treatment, as herein described, comprising an amino acid sequenceconsisting in a sequence selected from SEQ ID NO: 1, SEQ ID NO: 2, SEQID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, and SEQ ID NO: 7.

In another aspect, the invention provides a composition comprising asoluble CD146 protein as herein described and a pharmaceuticallyacceptable carrier. In another aspect, this composition furthercomprises a mature or immature endothelial cell, in particular anendothelial progenitor cell, and/or another angiogenic factor.

A pharmaceutical composition according to the present invention may alsocomprise, as the only biologically active agent, a mature or immatureendothelial cell which has been contacted with a human soluble CD146protein and/or which has been genetically modified to express a humanshort or soluble CD 146 protein.

In a further aspect, the invention relates to a protein or a compositionas herein described for use in the treatment or in the diagnosis of adisease, disorder or dysfunctional state leading to tissue ischemia orcharacterized by a decreased activation of a receptor for CD146, inparticular soluble CD146, or by a decreased expression of a geneselected from the gene encoding e-NOS, uPa, MMP-2 and KDR, compared tostandard expression, or for use in the prevention of ischemia.

In particular, the invention relates to the use of a protein or acomposition as herein described to prepare a composition for diagnosing,preventing or treating a disease, a disorder or a dysfunctional state asherein identified.

In a particular embodiment, the invention provides a method ofdiagnosing, preventing or treating a disease, a disorder or adysfunctional state in a mammal, preferably a human, as hereinidentified, in particular a method of diagnosing cancer (for examplebreast cancer, melanoma, etc.), or a method of preventing or treating atissue ischemia.

The method of diagnosing cancer preferably comprises a step of dosing,in the mammal serum, the amount of soluble CD146 protein.

The method of preventing or treating a tissue ischemia preferablycomprises a step of administering to the mammal, an effective amount ofa composition, as herein described, in particular a method comprising asoluble CD146 protein.

In a further aspect, the invention relates to the use of a protein or acomposition as herein described to improve the aesthetic appearance of ascar or, in prevention, to facilitate the cicatrization or healing of awound, a cut or an incision.

An object of the present invention is a protein or a composition asherein described for use in the cicatrization of a mammal epithelium, inparticular a human epithelium, in particular following a wound, a cut oran incision or in the context of a skin graft.

Another object of the present invention is a protein or a composition asherein described for use in the prevention or treatment of an eschar ora bedsore in a mammal, in particular a human.

A further object of the present invention is a protein or a compositionas herein described for use in the in the context of a skin graft in amammal, in particular a human.

A monoclonal antibody which selectively binds to the human soluble CD146protein comprising an amino acid sequence consisting in a sequenceselected from SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4,SEQ ID NO: 5, SEQ ID NO: 6 and SEQ ID NO: 7, is further herein provided.This antibody preferably also neutralizes a biological activity of thehuman soluble CD146 protein of the invention. Preferably, the antibodydecreases or inhibits neovascularization, vascular permeability and/orvascular endothelial cell growth in a mammal, preferably a human.

The antibody, or a pharmaceutical composition comprising said antibodyand a pharmaceutically acceptable carrier, herein disclosed, can be usedin a mammal, preferably a human, for preventing or treating a disease,disorder or dysfunctional state characterized by an undesirableexcessive neovascularization or vascular permeability, such as a cancer,by an overexpression or excessive activation of the soluble form ofCD146 and/or of a receptor for CD146, in particular soluble CD146, or byan excessive expression of a gene selected from the gene encoding e-NOS,uPa, MMP-2 and KDR, compared to standard expression.

In a further embodiment, the invention provides isolated nucleic acidmolecules encoding respectively a human soluble CD146 of the invention,the human short form of CD146, or recombinant forms thereof.

The nucleic acid molecule can be provided in a replicable vectorcomprising the nucleic acid molecule operably linked to controlsequences recognized by a host cell transfected or transformed with thevector, in particular a mature or immature endothelial cell or aprogenitor cell, preferably an endothelial progenitor cell. Theinvention further provides such an host cell comprising the vector orthe nucleic acid molecule.

In another aspect, the present disclosure provides kits comprising anyone or more of the herein-described protein, antibody, cell orcompositions. Typically, the kit also comprises instructions for usingthe protein, antibody, cell or composition according to the disclosedmethods.

LEGEND TO THE FIGURES

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication, withcolor drawing(s), will be provided by the Office upon request andpayment of the necessary fee.

FIG. 1: Chemotactic Activity of Recombinant Human Soluble CD146 in Vivoand in Vitro.

A: Microscopic examination of Matrigel plugs maintained for 12 days innormal mice. Control Matrigel plug containing either 1 μg/R1 PBS or 1μg/μl c-myc peptide and Matrigel plug containing 1 μg/μl rh-sCD146(soluble DC146) were injected in the same mouse. Capillary-likestructures were observed in the matrigel plugs in the presence ofrh-sCD146 (arrows). Immunostaining with anti-CD31 (green) and anti-CD117(red) antibodies in control or rh-sCD146 matrigel are shown. Nuclei werelabelled with dapi (blue).

B: Immunostaining of Matrigel plugs maintained for 12 days in nude miceinjected with 500,000 EPDC through the penian vein. Control Matrigelplugs containing 1 μg/μl c-myc peptide and Matrigel plugs containing 1μg/μl rh-sCD146 were injected in the same mouse. Immunostaining wasperformed in matrigel plugs with anti-human CD31 (red) antibody. Cellnuclei were labelled with dapi (blue).

C: Chemotactic effect of rh-sCD146 on EPC in vitro. 200,000 EPC in EBM2medium were seeded in the upper compartment of 8 μm pore size Transwellfilters. The following agents were added at various concentrations inthe medium in the lower compartment of the Transwell filter: rh-sCD146,the c-myc peptide, immunodepleted rh-sCD146 (Ip rh-sCD146), its control(IpC), or VEGF. Transwell filters were incubated overnight at 37° C.Cells were labelled with a fluorescent dye and fluorescence intensitywas measured. Results are the mean values+/−SEM of 4 differentexperiments. *, **, ***: P<0.05, P<0.01, P<0.001, experimental vsControl.

D: Immunostainings were performed with anti-CD45, anti-CD34, anti-αsma,anti-MOMA2, anti-CD31 and anti-CD117 antibodies on sections of matrigelplugs filled with rh-sCD146 and maintained for 12 days in normal mice.Nuclei were labelled with DAPI (blue). Co-labellings were also performedwith CD31/CD146, CD117/CD31, CD117/CD146, CD117/CD33 and CD117/CD45. Themerge pictures are given. Yellow areas correspond to a co-labelling. Insome pictures, these areas are better indicated with an arrow.

FIG. 2: Effect of Recombinant Human Soluble CD146 on Angiogenic Capacityof Endothelial Progenitor Derived Cells in Vitro

A: EPC capacity to elaborate pseudo-capillaries in Matrigel plugs wasevaluated in the presence or absence of different concentrations ofrh-sCD146, Fc-CD146 or control IgG1, the c-myc peptide, immunodepletedrh-sCD146 (Ip rh-sCD146) or its control (IpC), or VEGF. Number of tubeswas counted after 5 hours of incubation. Results are the meanvalues+/−SEM of 6 different experiments. *, **: P<0.05, P<0.01,experimental vs. Control.

B: The proliferation capacity of EPC was evaluated using theexperimental conditions described in (A). Results are the meanvalues+/−SEM of 5 different experiments. **, ***: P<0.01, P<0.001,experimental vs. Control.

C: The migration capacity of EPC was evaluated using the experimentalconditions described in (A). Results are the mean values+/−SEM of 4different experiments. *, ***: P<0.05, P<0.001, experimental vs.Control.

FIG. 3: Upregulation of Angiogenic Gene Transcripts and Products inEndothelial Progenitor-derived Cells in Response to Recombinant HumanSoluble CD146

A: Alterations in gene expression profiles were monitored in EPC treatedor not with 50 ng/ml rh-sCD146 for 3 h using oligo-arrays specific forangiogenic pathways. Gene expression alterations were confirmed by qPCR.Results are mean value of 4 different experiments. *, **: P<0.05,P<0.01, experimental vs. Control.

B: Western-blot analysis was performed to confirm protein up-regulationof MMP-2, e-NOS, uPA, KDR (also called VEGFR2) and to establish thekinetics of induction. A representative experiment is shown for eachprotein.

C: Quantification of 3-5 experiments described in B. *, **, ***: P<0.05,P<0.01, P<0,001, experimental vs. Control.

FIG. 4: Effect of Local Injection of Recombinant Human Soluble CD146 ina Rat Ischemic Hind Limb Model

A: Rats underwent surgery to induce ischemia in the hind limb. Thefollowing day, rats were subjected to a daily local injection ofsolution containing either 10 μg/ml of c-myc peptide or 10 μg/ml ofrh-sCD 146 for 5 or 12 days. Animals were analyzed every 5 days for 20days after surgery for auto-amputation level and blood perfusion rate(laser-doppler analysis). Results are mean values of 9 different animalsin each group. *: P<0.05, experimental vs. Control.

B: Histochemical examination was performed on hind limb muscle sectionsfrom control non-treated, c-myc peptide-treated or rh-sCD146-treatedrats 12 days after surgery.

C: Estimation of the effects observed by histochemical examination incontrol animals, c-myc treated and rh-sCD146 treated rats (12 days) oninflammation and fibrosis levels, amount of necrosed fibers,angiogenesis and muscle aspect. Semi-quantifications definedas—(absence), +/−(low expression),+(intermediate expression),++(highexpression) are given.

D: Co-immunostainings were performed with anti-CD117 (green) andanti-CD146 (red) antibodies in muscle sections of ischemic rats treatedfor 2 days with rh-sCD146 or not (Control). Nuclei were labelled withDAPI (blue). The merge pictures are given. Yellow areas correspond to aco-labelling (indicated with an arrow).

FIG. 5: Additive Effect of rh-sCD146 and VEGF on Angiogenic Capacity ofEndothelial Progenitor Cells in Vitro

A: Proliferation capacity of late EPC was evaluated when rh-sCD 146 (50ng/ml) and VEGF (20 ng/ml) were added together and compared to theeffect of each growth factor added separately. Results are the meanvalues+/−SEM of 4 different experiments.

B: Migration capacity of late EPC was evaluated using a wound healingassay when rh-sCD146 (50 ng/ml) and VEGF (20 ng/ml) were added togetherand compared to the effect of each growth factor added separately.Results are the mean values+/−SEM of 4 different experiments.

C: EPC capacity to elaborate pseudo-capillaries in matrigel plugs wasevaluated in different conditions. Number of capillary-like structureswas evaluated when rh-sCD146 (50 ng/ml) and VEGF (20 ng/ml) were addedtogether and compared to the effect of each growth factor addedseparately. In addition, the effect of an anti-VEGFR2 antibody (Ab)preincubated before growth factor(s) addition was tested in controlcondition (Ab), in the presence of rh-sCD146 (Ab+rh-sCD146), in thepresence of VEGF (Ab+VEGF) and in the presence of the two growth factors(Ab+rh-sCD146+VEGF). In a last condition, (Washed Ab+rh-sCD146+VEGF),the antibody was preincubated, then washed before addition of the twogrowth factors. Number of tubes was counted after 5 hours of incubation.Results are the mean values+/−SEM of 6 different experiments. **:P<0.01, ***: P<0.001, experimental vs. Control.

FIG. 6: Characterization of Anti-sCD146 Antibodies.

Antibodies were tested for their ability to bind soluble CD146 (A) butnot membrane CD146 (B) by flow cytometry analysis on sCD146 coupled toprotein G beads and Huvec, respectively. 6 different antibodiesdisplaying a binding on sCD146 but not on membrane CD146 are shown. ***:p<0.001; $, $$: p<0.01, p<0.001, Ab+sCD146 vs sCD146.

FIG. 7: Blocking Effect of Anti-sCD146 Antibodies on the sCD146-inducedIncrease in EPC Proliferation.

Antibodies able to bind soluble CD146 but not membrane CD146 were testedfor their capacity to inhibit sCD146 effect on EPC proliferation. Amongthese antibodies, 6 antibodies significantly blocked the sCD146-inducedEPC proliferation. ***: p<0.001; $, $$: p<0.01, p<0.001, Ab+sCD146 vssCD146.

FIG. 8: Effect of Recombinant Human Soluble CD146 on Proliferation ofHuman Keratinocytes:

The effect of different concentrations of soluble CD146 was tested onthe proliferation capacity of human keratinocytes. Results are the meanvalues+/−SEM of 4 different experiments. *: P<0.05, experimental vs.control (C).

DETAILED DESCRIPTION OF THE INVENTION

In the below description of the invention, the following terms will beemployed and are intended to be defined as indicated below.

“Human long CD146 protein” or “long CD146” refers to a human protein,peptide or amino acid molecule, mainly present in the membrane ofendothelial cells and having an amino acid sequence corresponding to thefollowing SEQ ID NO: 8:

MGLPRLVCAFLLAACCCCPRVAGVPGEAEQPAPELVEVEVGSTALLKCGLSQSQGNLSHVDWFSVHKEKRTLIFRVRQGQGQSEPGEYEQRLSLQDRGATLALTQVTPQDERIFLCQGKRPRSQEYRIQLRVYKAPEEPNIQVNPLGIPVNSKEPEEVATCVGRNGYPIPQVIWYKNGRPLKEEKNRVHIQSSQTVESSGLYTLQSILKAQLVKEDKDAQFYCELNYRLPSGNHMKESREVTVPVFYPTEKVWLEVEPVGMLKEGDRVEIRCLADGNPPPHFSISKQNPSTREAEEETTNDNGVLVLEPARKEHSGRYECQAWNLDTMISLLSEPQELLVNYVSDVRVSPAAPERQEGSSLTLTCEAESSQDLEFQWLREETDQVLERGPVLQLHDLKREAGGGYRCVASVPSIPGLNRTQLVKLAIFGPPWMAFKERKVWVKENMVLNLSCEASGHPRPTISWNVNGTASEQDQDPQRVLSTLNVLVTPELLETGVECTASNDLGKNTSILFLELVNLTTLTPDSNTTTGLSTSTASPHTRANSTSTERKLPEPESRGVVIVAVIVCILVLAVLGAVLYFLYKKGKLPCRRSGKQEITLPPSRKTELVVEVKSDKLPEEMGLLQGSSGDKRAPGDQGEKYIDLRH

“Human short CD146 protein” or “short CD146” refers to a human protein,peptide or amino acid molecule mainly present in the membrane ofendothelial cells and having an amino acid sequence corresponding to thefollowing SEQ ID NO: 9:

MGLPRLVCAFLLAACCCCPRVAGVPGEAEQPAPELVEVEVGSTALLKCGLSQSQGNLSHVDWFSVHKEKRTLIFRVRQGQGQSEPGEYEQRLSLQDRGATLALTQVTPQDERIFLCQGKRPRSQEYRIQLRVYKAPEEPNIQVNPLGIPVNSKEPEEVATCVGRNGYPIPQVIWYKNGRPLKEEKNRVHIQSSQTVESSGLYTLQSILKAQLVKEDKDAQFYCELNYRLPSGNHMKESREVTVPVFYPTEKVWLEVEPVGMLKEGDRVEIRCLADGNPPPHFSISKQNPSTREAEEETTNDNGVLVLEPARKEHSGRYECQAWNLDTMISLLSEPQELLVNYVSDVRVSPAAPERQEGSSLTLTCEAESSQDLEFQWLREETDQVLERGPVLQLHDLKREAGGGYRCVASVPSIPGLNRTQLVKLAIFGPPWMAFKERKVWVKENMVLNLSCEASGHPRPTISWNVNGTASEQDQDPQRVLSTLNVLVTPELLETGVECTASNDLGKNTSILFLELVNLTTLTPDSNTTTGLSTSTASPHTRANSTSTERKLPEPESRGVVIVAVIVCILVLAVLGAVLYFLYKKGKLPCRRSGKQEMER NTSI

“Human soluble CD146 protein” or “soluble CD146” refers to a humanprotein, peptide or amino acid molecule containing about 552 to about558 amino acids, preferably 558 amino acids, even more preferably 557,556, 555, 554, 553 or 552 amino acids.

An example of a human soluble CD146 protein according to the presentinvention comprises at least residues 1 to 552 inclusive, preferably atleast residues 1 to 557 inclusive, of the amino acid sequence SEQ ID NO:8.

In a particular embodiment, the invention provides a protein comprisingan amino acid sequence consisting in SEQ ID NO: 1:MGLPRLVCAFLLAACCCCPRVAGVPGEAEQPAPELVEVEVGSTALLKCGLSQSQGNLSHVDWFSVHKEKRTLIFRVRQGQGQSEPGEYEQRLSLQDRGATLALTQVTPQDERIFLCQGKRPRSQEYRIQLRVYKAPEEPNIQVNPLGIPVNSKEPEEVATCVGRNGYPIPQVIWYKNGRPLKEEKNRVHIQSSQTVESSGLYTLQSILKAQLVKEDKDAQFYCELNYRLPSGNHMKESREVTVPVFYPTEKVWLEVEPVGMLKEGDRVEIRCLADGNPPPHFSISKQNPSTREAEEETTNDNGVLVLEPARKEHSGRYECQAWNLDTMISLLSEPQELLVNYVSDVRVSPAAPERQEGSSLTLTCEAESSQDLEFQWLREETDQVLERGPVLQLHDLKREAGGGYRCVASVPSIPGLNRTQLVKLAIFGPPWMAFKERKVWVKENMVLNLSCEASGHPRPTISWNVNGTASEQDQDPQRVLSTLNVLVTPELLETGVECTASNDLGKNTSILFLELVNLTTLTPDSNTTTGLSTSTASPHTRANSTSTERKL, which corresponds to a preferred humansoluble CD146 protein usable in the context of a mammal treatment, inparticular a human treatment, as herein described.

Another human soluble CD146 protein usable in the context of a mammaltreatment has an amino acid sequence consisting in one of the belowidentified sequences:

SEQ ID NO: 2: MGLPRLVCAFLLAACCCCPRVAGVPGEAEQPAPELVEVEVGSTALLKCGLSQSQGNLSHVDWFSVHKEKRTLIFRVRQGQGQSEPGEYEQRLSLQDRGATLALTQVTPQDERIFLCQGKRPRSQEYRIQLRVYKAPEEPNIQVNPLGIPVNSKEPEEVATCVGRNGYPIPQVIWYKNGRPLKEEKNRVHIQSSQTVESSGLYTLQSILKAQLVKEDKDAQFYCELNYRLPSGNHMKESREVTVPVFYPTEKVWLEVEPVGMLKEGDRVEIRCLADGNPPPHFSISKQNPSTREAEEETTNDNGVLVLEPARKEHSGRYECQAWNLDTMISLLSEPQELLVNYVSDVRVSPAAPERQEGSSLTLTCEAESSQDLEFQWLREETDQVLERGPVLQLHDLKREAGGGYRCVASVPSIPGLNRTQLVKLAIFGPPWMAFKERKVWVKENMVLNLSCEASGHPRPTISWNVNGTASEQDQDPQRVLSTLNVLVTPELLETGVECTASNDLGKNTSILFLELVNLTTLTPDSNTTTGLSTSTASPHTRANSTSTERKLP SEQ ID NO: 3:MGLPRLVCAFLLAACCCCPRVAGVPGEAEQPAPELVEVEVGSTALLKCGLSQSQGNLSHVDWFSVHKEKRTLIFRVRQGQGQSEPGEYEQRLSLQDRGATLALTQVTPQDERIFLCQGKRPRSQEYRIQLRVYKAPEEPNIQVNPLGIPVNSKEPEEVATCVGRNGYPIPQVIWYKNGRPLKEEKNRVHIQSSQTVESSGLYTLQSILKAQLVKEDKDAQFYCELNYRLPSGNHMKESREVTVPVFYPTEKVWLEVEPVGMLKEGDRVEIRCLADGNPPPHFSISKQNPSTREAEEETTNDNGVLVLEPARKEHSGRYECQAWNLDTMISLLSEPQELLVNYVSDVRVSPAAPERQEGSSLTLTCEAESSQDLEFQWLREETDQVLERGPVLQLHDLKREAGGGYRCVASVPSIPGLNRTQLVKLAIFGPPWMAFKERKVWVKENMVLNLSCEASGHPRPTISWNVNGTASEQDQDPQRVLSTLNVLVTPELLETGVECTASNDLGKNTSILFLELVNLTTLTPDSNTTTGLSTSTASPHTRANSTSTERKLPE SEQ ID NO: 4:MGLPRLVCAFLLAACCCCPRVAGVPGEAEQPAPELVEVEVGSTALLKCGLSQSQGNLSHVDWFSVHKEKRTLIFRVRQGQGQSEPGEYEQRLSLQDRGATLALTQVTPQDERIFLCQGKRPRSQEYRIQLRVYKAPEEPNIQVNPLGIPVNSKEPEEVATCVGRNGYPIPQVIWYKNGRPLKEEKNRVHIQSSQTVESSGLYTLQSILKAQLVKEDKDAQFYCELNYRLPSGNHMKESREVTVPVFYPTEKVWLEVEPVGMLKEGDRVEIRCLADGNPPPHFSISKQNPSTREAEEETTNDNGVLVLEPARKEHSGRYECQAWNLDTMISLLSEPQELLVNYVSDVRVSPAAPERQEGSSLTLTCEAESSQDLEFQWLREETDQVLERGPVLQLHDLKREAGGGYRCVASVPSIPGLNRTQLVKLAIFGPPWMAFKERKVWVKENMVLNLSCEASGHPRPTISWNVNGTASEQDQDPQRVLSTLNVLVTPELLETGVECTASNDLGKNTSILFLELVNLTTLTPDSNTTTGLSTSTASPHTRANSTSTERKLPEP SEQ ID NO: 5:MGLPRLVCAFLLAACCCCPRVAGVPGEAEQPAPELVEVEVGSTALLKCGLSQSQGNLSHVDWFSVHKEKRTLIFRVRQGQGQSEPGEYEQRLSLQDRGATLALTQVTPQDERIFLCQGKRPRSQEYRIQLRVYKAPEEPNIQVNPLGIPVNSKEPEEVATCVGRNGYPIPQVIWYKNGRPLKEEKNRVHIQSSQTVESSGLYTLQSILKAQLVKEDKDAQFYCELNYRLPSGNHMKESREVTVPVFYPTEKVWLEVEPVGMLKEGDRVEIRCLADGNPPPHFSISKQNPSTREAEEETTNDNGVLVLEPARKEHSGRYECQAWNLDTMISLLSEPQELLVNYVSDVRVSPAAPERQEGSSLTLTCEAESSQDLEFQWLREETDQVLERGPVLQLHDLKREAGGGYRCVASVPSIPGLNRTQLVKLAIFGPPWMAFKERKVWVKENMVLNLSCEASGHPRPTISWNVNGTASEQDQDPQRVLSTLNVLVTPELLETGVECTASNDLGKNTSILFLELVNLTTLTPDSNTTTGLSTSTASPHTRANSTSTERKLPEPE SEQ ID NO: 6:MGLPRLVCAFLLAACCCCPRVAGVPGEAEQPAPELVEVEVGSTALLKCGLSQSQGNLSHVDWFSVHKEKRTLIFRVRQGQGQSEPGEYEQRLSLQDRGATLALTQVTPQDERIFLCQGKRPRSQEYRIQLRVYKAPEEPNIQVNPLGIPVNSKEPEEVATCVGRNGYPIPQVIWYKNGRPLKEEKNRVHIQSSQTVESSGLYTLQSILKAQLVKEDKDAQFYCELNYRLPSGNHMKESREVTVPVFYPTEKVWLEVEPVGMLKEGDRVEIRCLADGNPPPHFSISKQNPSTREAEEETTNDNGVLVLEPARKEHSGRYECQAWNLDTMISLLSEPQELLVNYVSDVRVSPAAPERQEGSSLTLTCEAESSQDLEFQWLREETDQVLERGPVLQLHDLKREAGGGYRCVASVPSIPGLNRTQLVKLAIFGPPWMAFKERKVWVKENMVLNLSCEASGHPRPTISWNVNGTASEQDQDPQRVLSTLNVLVTPELLETGVECTASNDLGKNTSILFLELVNLTTLTPDSNTTTGLSTSTASPHTRANSTSTERKLPEPES SEQ ID NO: 7:MGLPRLVCAFLLAACCCCPRVAGVPGEAEQPAPELVEVEVGSTALLKCGLSQSQGNLSHVDWFSVHKEKRTLIFRVRQGQGQSEPGEYEQRLSLQDRGATLALTQVTPQDERIFLCQGKRPRSQEYRIQLRVYKAPEEPNIQVNPLGIPVNSKEPEEVATCVGRNGYPIPQVIWYKNGRPLKEEKNRVHIQSSQTVESSGLYTLQSILKAQLVKEDKDAQFYCELNYRLPSGNHMKESREVTVPVFYPTEKVWLEVEPVGMLKEGDRVEIRCLADGNPPPHFSISKQNPSTREAEEETTNDNGVLVLEPARKEHSGRYECQAWNLDTMISLLSEPQELLVNYVSDVRVSPAAPERQEGSSLTLTCEAESSQDLEFQWLREETDQVLERGPVLQLHDLKREAGGGYRCVASVPSIPGLNRTQLVKLAIFGPPWMAFKERKVWVKENMVLNLSCEASGHPRPTISWNVNGTASEQDQDPQRVLSTLNVLVTPELLETGVECTASNDLGKNTSILFLELVNLTTLTPDSNTTTGLSTSTASPHTRANSTSTERKLPEPESR

Among the previous sequences, SEQ ID NO: 1 and SEQ ID NO: 6 areparticularly preferred. The soluble CD146 is present in the human serumand extracted therefrom or artificially reproduced. In a preferredembodiment, the soluble CD146 contains the amino acid sequenceconsisting in SEQ ID NO: 1 or SEQ ID NO: 6. Preferably, the hereindisclosed human soluble CD146 is a biologically active human solubleCD146, i.e., it initiates, promotes, increases or stimulatesvasculogenesis and/or angiogenesis in vitro, ex vivo or in vivo.Preferably the soluble CD146 displays a chemotactic activity, i.e., thesoluble CD146 is able to induce mobilization or migration of endogeneousor exogeneous cells to the site wherein vasculogenesis and/orangiogenesis is to occurred, preferably cells of endothelial origin(KDR+ and/or CD31+ cells), preferably selected from immature endothelialcells (in particular CD117+ cells), mature endothelial cells (inparticular KDR+ cells), endothelial progenitor cells (EPC), such as stemcell (typically bone-marrow derived stem cells), and mixtures thereof,and/or allows or favors the organization of such cells intovascular-like structures. A biologically active human soluble CD146 isalso able to activate endothelial cells as defined previously, i.e., toincrease their ability to proliferate and/or promote pseudo-capillariesgenesis.

The herein disclosed human soluble CD146 is further preferably capableof interacting with the short isoform of CD146 (“short CD 146”), areceptor of CD146, in particular a receptor of soluble CD146, and/or toa complex comprising such a short isoform of CD146 and receptor ofsoluble CD146, on a cell preferably selected from the above identifiedcells.

A typical human soluble CD146 protein according to the present inventionis, as explained previously, a protein usable in the context of atreatment (a therapeutic or prophylactic protein) or in the context ofdiagnostic, and compatible with an administration to a human, inparticular by way of injection in the bloodstream, and/or by way ofsubcutaneous and/or intramuscular administration.

The term “Treatment” refers to both therapeutic and prophylactic orpreventive treatment or measures able to alleviate or cure a disease,disorder or dysfunctional state. Such a treatment is intended for amammal subject, preferably a human subject in need thereof. Areconsidered as such, the subjects suffering from a disease, disorder ordysfunctional state leading to tissue ischemia, or those considered “atrisk of developing” such a disease, disorder or dysfunctional state, inwhich this has to be prevented.

Disease, disorder or dysfunctional state leading to tissue ischemia aredisease, disorder or dysfunctional state leading to abnormalvasculogenesis and/or angiogenesis, in particular disease, disorder ordysfunctional state leading to an undesirable excessiveneovascularization, vascular permeability (alteration of theintercellular junctions of endothelial cells) and/or vascularendothelial cell growth. Examples of such disease include cancer;diabetes; age-related macular degeneration; rheumatoid arthritis;psoriasis; any known vascular diseases including atheroscleroticvascular disease, cardiovascular disease such as coronary arterydisease, ischemic heart disease and stroke, cerebrovascular ischemia,peripheral vascular disease such as peripheral artery occlusive disease.

In these conditions leading to an undesirable neovascularization, newblood vessels feed diseased tissues, destroy normal tissues, and in thecase of cancer, the new vessels allow tumor cells to escape into thecirculation and lodge in other organs (tumor metastases).

Disorders may be the consequence of a disease as described above or of atrauma. Typical disorders are for example inflammation, oedema, fibrosisor necrosis.

Examples of dysfunctional states are characterized by a lack of or, onthe contrary, an excessive expression of at least one particular form ofCD146 or of a receptor for CD146, in particular for soluble CD146,compared to a standard expression. Other Examples of dysfunctionalstates are characterized by a decreased or excessive expression of agene selected from the gene encoding e-NOS, uPa, MMP-2 and KDR, comparedto a standard expression.

Dysfunctional states characterized by a lack of expression areadvantageously treated by a human soluble CD146, or a therapeuticcomposition comprising such a soluble CD146, or a cell (as describedbelow) according to the present invention.

Dysfunctional states characterized by an excessive expression, such ascancer, are advantageously treated by an antibody directed against ahuman soluble CD146, or any other antagonist directed against such ahuman soluble CD146, as herein described. In a particular embodiment, adysfunctional state such as a cancer, may be treated by an antibodydirected against a human soluble CD146 together with an antibodydirected against an angiogenic factor such as VEGF.

The present description therefore identifies an isolated human solubleCD146 protein containing about 552 to 558 amino acids, preferably 552 to557 amino acids, even more preferably 552 or 557 amino acids. “Isolated”means identified and separated or recovered from a component of itsnatural source or environment in a human subject, in particular frombone marrow or blood of said subject.

A preferred human soluble CD146 protein comprises an amino acid sequenceconsisting in SEQ ID NO: 1 or SEQ ID NO: 6, and corresponds to a proteinusable in the context of a mammal treatment, in particular a humantreatment, as herein described.

The present description further provides nucleic acid molecules whichrespectively encode the proteins of the invention herein described.

Such nucleic acid molecules are RNA or DNA that preferably each encode abiologically active human CD146, in particular a human soluble CD146 ofthe invention, the human short form of CD146, and recombinant formsthereof.

Examples of nucleic acid sequences are provided below:

SEQ ID NO: 17 (short CD146)ATGGGGCTTCCCAGGCTGGTCTGCGCCTTCTTGCTCGCCGCCTGCTGCTGCTGTCCTCGCGTCGCGGGTGTGCCCGGAGAGGCTGAGCAGCCTGCGCCTGAGCTGGTGGAGGTGGAAGTGGGCAGCACAGCCCTTCTGAAGTGCGGCCTCTCCCAGTCCCAAGGCAACCTCAGCCATGTCGACTGGTTTTCTGTCCACAAGGAGAAGCGGACGCTCATCTTCCGTGTGCGCCAGGGCCAGGGCCAGAGCGAACCTGGGGAGTACGAGCAGCGGCTCAGCCTCCAGGACAGAGGGGCTACTCTGGCCCTGACTCAAGTCACCCCCCAAGACGAGCGCATCTTCTTGTGCCAGGGCAAGCGCCCTCGGTCCCAGGAGTACCGCATCCAGCTCCGCGTCTACAAAGCTCCGGAGGAGCCAAACATCCAGGTCAACCCCCTGGGCATCCCTGTGAACAGTAAGGAGCCTGAGGAGGTCGCTACCTGTGTAGGGAGGAACGGGTACCCCATTCCTCAAGTCATCTGGTACAAGAATGGCCGGCCTCTGAAGGAGGAGAAGAACCGGGTCCACATTCAGTCGTCCCAGACTGTGGAGTCGAGTGGTTTGTACACCTTGCAGAGTATTCTGAAGGCACAGCTGGTTAAAGAAGACAAAGATGCCCAGTTTTACTGTGAGCTCAACTACCGGCTGCCCAGTGGGAACCACATGAAGGAGTCCAGGGAAGTCACCGTCCCTGTTTTCTACCCGACAGAAAAAGTGTGGCTGGAAGTGGAGCCCGTGGGAATGCTGAAGGAAGGGGACCGCGTGGAAATCAGGTGTTTGGCTGATGGCAACCCTCCACCACACTTCAGCATCAGCAAGCAGAACCCCAGCACCAGGGAGGCAGAGGAAGAGACAACCAACGACAACGGGGTCCTGGTGCTGGAGCCTGCCCGGAAGGAACACAGTGGGCGCTATGAATGTCAGGGCCTGGACTTGGACACCATGATATCGCTGCTGAGTGAACCACAGGAACTACTGGTGAACTATGTGTCTGACGTCCGAGTGAGTCCCGCAGCCCCTGAGAGACAGGAAGGCAGCAGCCTCACCCTGACCTGTGAGGCAGAGAGTAGCCAGGACCTCGAGTTCCAGTGGCTGAGAGAAGAGACAGGCCAGGTGCTGGAAAGGGGGCCTGTGCTTCAGTTGCATGACCTGAAACGGGAGGCAGGAGGCGGCTATCGCTGCGTGGCGTCTGTGCCCAGCATACCCGGCCTGAACCGCACACAGCTGGTCAACGTGGCCATTTTTGGCCCCCCTTGGATGGCATTCAAGGAGAGGAAGGTGTGGGTGAAAGAGAATATGGTGTTGAATCTGTCTTGTGAAGCGTCAGGGCACCCCCGGCCCACCATCTCCTGGAACGTCAACGGCACGGCAAGTGAACAAGACCAAGATCCACAGCGAGTCCTGAGCACCCTGAATGTCCTCGTGACCCCGGAGCTGTTGGAGACAGGTGTTGAATGCACGGCCTCCAACGACCTGGGCAAAAACACCAGCATCCTCTTCCTGGAGCTGGTCAATTTAACCACCCTCACACCAGACTCCAACACAACCACTGGCCTCAGCACTTCCACTGCCAGTCCTCATACCAGAGCCAACAGCACCTCCACAGAGAGAAAGCTGCCGGAGCCGGAGAGCCGGGGCGTGGTCATCGTGGCTGTGATTGTGTGCATCCTGGTCCTGGCGGTGCTGGGCGCTGTCCTCTATTTCCTCTATAAGAAGGGCAAGCTGCCGTGCAGGAGCTCAGGGAAGCAGGAGATGGAGAGAAATACATCGATCTGA SEQ ID NO: 10 (soluble CD146)ATGGGGCTTCCCAGGCTGGTCTGCGCCTTCTTGCTCGCCGCCTGCTGCTGCTGTCCTCGCGTCGCGGGTGTGCCCGGAGAGGCTGAGCAGCCTGCGCCTGAGCTGGTGGAGGTGGAAGTGGGCAGCACAGCCCTTCTGAAGTGCGGCCTCTCCCAGTCCCAAGGCAACCTCAGCCATGTCGACTGGTTTTCTGTCCACAAGGAGAAGCGGACGCTCATCTTCCGTGTGCGCCAGGGCCAGGGCCAGAGCGAACCTGGGGAGTACGAGCAGCGGCTCAGCCTCCAGGACAGAGGGGCTACTCTGGCCCTGACTCAAGTCACCCCCCAAGACGAGCGCATCTTCTTGTGCCAGGGCAAGCGCCCTCGGTCCCAGGAGTACCGCATCCAGCTCCGCGTCTACAAAGCTCCGGAGGAGCCAAACATCCAGGTCAACCCCCTGGGCATCCCTGTGAACAGTAAGGAGCCTGAGGAGGTCGCTACCTGTGTAGGGAGGAACGGGTACCCCATTCCTCAAGTCATCTGGTACAAGAATGGCCGGCCTCTGAAGGAGGAGAAGAACCGGGTCCACATTCAGTCGTCCCAGACTGTGGAGTCGAGTGGTTTGTACACCTTGCAGAGTATTCTGAAGGCACAGCTGGTTAAAGAAGACAAAGATGCCCAGTTTTACTGTGAGCTCAACTACCGGCTGCCCAGTGGGAACCACATGAAGGAGTCCAGGGAAGTCACCGTCCCTGTTTTCTACCCGACAGAAAAAGTGTGGCTGGAAGTGGAGCCCGTGGGAATGCTGAAGGAAGGGGACCGCGTGGAAATCAGGTGTTTGGCTGATGGCAACCCTCCACCACACTTCAGCATCAGCAAGCAGAACCCCAGCACCAGGGAGGCAGAGGAAGAGACAACCAACGACAACGGGGTCCTGGTGCTGGAGCCTGCCCGGAAGGAACACAGTGGGCGCTATGAATGTCAGGGCCTGGACTTGGACACCATGATATCGCTGCTGAGTGAACCACAGGAACTACTGGTGAACTATGTGTCTGACGTCCGAGTGAGTCCCGCAGCCCCTGAGAGACAGGAAGGCAGCAGCCTCACCCTGACCTGTGAGGCAGAGAGTAGCCAGGACCTCGAGTTCCAGTGGCTGAGAGAAGAGACAGGCCAGGTGCTGGAAAGGGGGCCTGTGCTTCAGTTGCATGACCTGAAACGGGAGGCAGGAGGCGGCTATCGCTGCGTGGCGTCTGTGCCCAGCATACCCGGCCTGAACCGCACACAGCTGGTCAACGTGGCCATTTTTGGCCCCCCTTGGATGGCATTCAAGGAGAGGAAGGTGTGGGTGAAAGAGAATATGGTGTTGAATCTGTCTTGTGAAGCGTCAGGGCACCCCCGGCCCACCATCTCCTGGAACGTCAACGGCACGGCAAGTGAACAAGACCAAGATCCACAGCGAGTCCTGAGCACCCTGAATGTCCTCGTGACCCCGGAGCTGTTGGAGACAGGTGTTGAATGCACGGCCTCCAACGACCTGGGCAAAAACACCAGCATCCTCTTCCTGGAGCTGGTCAATTTAACCACCCTCACACCAGACTCCAACACAACCACTGGCCTCAGCACTTCCACTGCCAGTCCTCATACCAGAGCCAACAGCACCTCCACAGAGAGAAAGCTG SEQ ID NO: 11 (soluble CD146)ATGGGGCTTCCCAGGCTGGTCTGCGCCTTCTTGCTCGCCGCCTGCTGCTGCTGTCCTCGCGTCGCGGGTGTGCCCGGAGAGGCTGAGCAGCCTGCGCCTGAGCTGGTGGAGGTGGAAGTGGGCAGCACAGCCCTTCTGAAGTGCGGCCTCTCCCAGTCCCAAGGCAACCTCAGCCATGTCGACTGGTTTTCTGTCCACAAGGAGAAGCGGACGCTCATCTTCCGTGTGCGCCAGGGCCAGGGCCAGAGCGAACCTGGGGAGTACGAGCAGCGGCTCAGCCTCCAGGACAGAGGGGCTACTCTGGCCCTGACTCAAGTCACCCCCCAAGACGAGCGCATCTTCTTGTGCCAGGGCAAGCGCCCTCGGTCCCAGGAGTACCGCATCCAGCTCCGCGTCTACAAAGCTCCGGAGGAGCCAAACATCCAGGTCAACCCCCTGGGCATCCCTGTGAACAGTAAGGAGCCTGAGGAGGTCGCTACCTGTGTAGGGAGGAACGGGTACCCCATTCCTCAAGTCATCTGGTACAAGAATGGCCGGCCTCTGAAGGAGGAGAAGAACCGGGTCCACATTCAGTCGTCCCAGACTGTGGAGTCGAGTGGTTTGTACACCTTGCAGAGTATTCTGAAGGCACAGCTGGTTAAAGAAGACAAAGATGCCCAGTTTTACTGTGAGCTCAACTACCGGCTGCCCAGTGGGAACCACATGAAGGAGTCCAGGGAAGTCACCGTCCCTGTTTTCTACCCGACAGAAAAAGTGTGGCTGGAAGTGGAGCCCGTGGGAATGCTGAAGGAAGGGGACCGCGTGGAAATCAGGTGTTTGGCTGATGGCAACCCTCCACCACACTTCAGCATCAGCAAGCAGAACCCCAGCACCAGGGAGGCAGAGGAAGAGACAACCAACGACAACGGGGTCCTGGTGCTGGAGCCTGCCCGGAAGGAACACAGTGGGCGCTATGAATGTCAGGGCCTGGACTTGGACACCATGATATCGCTGCTGAGTGAACCACAGGAACTACTGGTGAACTATGTGTCTGACGTCCGAGTGAGTCCCGCAGCCCCTGAGAGACAGGAAGGCAGCAGCCTCACCCTGACCTGTGAGGCAGAGAGTAGCCAGGACCTCGAGTTCCAGTGGCTGAGAGAAGAGACAGGCCAGGTGCTGGAAAGGGGGCCTGTGCTTCAGTTGCATGACCTGAAACGGGAGGCAGGAGGCGGCTATCGCTGCGTGGCGTCTGTGCCCAGCATACCCGGCCTGAACCGCACACAGCTGGTCAACGTGGCCATTTTTGGCCCCCCTTGGATGGCATTCAAGGAGAGGAAGGTGTGGGTGAAAGAGAATATGGTGTTGAATCTGTCTTGTGAAGCGTCAGGGCACCCCCGGCCCACCATCTCCTGGAACGTCAACGGCACGGCAAGTGAACAAGACCAAGATCCACAGCGAGTCCTGAGCACCCTGAATGTCCTCGTGACCCCGGAGCTGTTGGAGACAGGTGTTGAATGCACGGCCTCCAACGACCTGGGCAAAAACACCAGCATCCTCTTCCTGGAGCTGGTCAATTTAACCACCCTCACACCAGACTCCAACACAACCACTGGCCTCAGCACTTCCACTGCCAGTCCTCATACCAGAGCCAACAGCACCTCCACAGAGAGAAAGCTGCCG SEQ ID NO: 12 (soluble CD146)ATGGGGCTTCCCAGGCTGGTCTGCGCCTTCTTGCTCGCCGCCTGCTGCTGCTGTCCTCGCGTCGCGGGTGTGCCCGGAGAGGCTGAGCAGCCTGCGCCTGAGCTGGTGGAGGTGGAAGTGGGCAGCACAGCCCTTCTGAAGTGCGGCCTCTCCCAGTCCCAAGGCAACCTCAGCCATGTCGACTGGTTTTCTGTCCACAAGGAGAAGCGGACGCTCATCTTCCGTGTGCGCCAGGGCCAGGGCCAGAGCGAACCTGGGGAGTACGAGCAGCGGCTCAGCCTCCAGGACAGAGGGGCTACTCTGGCCCTGACTCAAGTCACCCCCCAAGACGAGCGCATCTTCTTGTGCCAGGGCAAGCGCCCTCGGTCCCAGGAGTACCGCATCCAGCTCCGCGTCTACAAAGCTCCGGAGGAGCCAAACATCCAGGTCAACCCCCTGGGCATCCCTGTGAACAGTAAGGAGCCTGAGGAGGTCGCTACCTGTGTAGGGAGGAACGGGTACCCCATTCCTCAAGTCATCTGGTACAAGAATGGCCGGCCTCTGAAGGAGGAGAAGAACCGGGTCCACATTCAGTCGTCCCAGACTGTGGAGTCGAGTGGTTTGTACACCTTGCAGAGTATTCTGAAGGCACAGCTGGTTAAAGAAGACAAAGATGCCCAGTTTTACTGTGAGCTCAACTACCGGCTGCCCAGTGGGAACCACATGAAGGAGTCCAGGGAAGTCACCGTCCCTGTTTTCTACCCGACAGAAAAAGTGTGGCTGGAAGTGGAGCCCGTGGGAATGCTGAAGGAAGGGGACCGCGTGGAAATCAGGTGTTTGGCTGATGGCAACCCTCCACCACACTTCAGCATCAGCAAGCAGAACCCCAGCACCAGGGAGGCAGAGGAAGAGACAACCAACGACAACGGGGTCCTGGTGCTGGAGCCTGCCCGGAAGGAACACAGTGGGCGCTATGAATGTCAGGGCCTGGACTTGGACACCATGATATCGCTGCTGAGTGAACCACAGGAACTACTGGTGAACTATGTGTCTGACGTCCGAGTGAGTCCCGCAGCCCCTGAGAGACAGGAAGGCAGCAGCCTCACCCTGACCTGTGAGGCAGAGAGTAGCCAGGACCTCGAGTTCCAGTGGCTGAGAGAAGAGACAGGCCAGGTGCTGGAAAGGGGGCCTGTGCTTCAGTTGCATGACCTGAAACGGGAGGCAGGAGGCGGCTATCGCTGCGTGGCGTCTGTGCCCAGCATACCCGGCCTGAACCGCACACAGCTGGTCAACGTGGCCATTTTTGGCCCCCCTTGGATGGCATTCAAGGAGAGGAAGGTGTGGGTGAAAGAGAATATGGTGTTGAATCTGTCTTGTGAAGCGTCAGGGCACCCCCGGCCCACCATCTCCTGGAACGTCAACGGCACGGCAAGTGAACAAGACCAAGATCCACAGCGAGTCCTGAGCACCCTGAATGTCCTCGTGACCCCGGAGCTGTTGGAGACAGGTGTTGAATGCACGGCCTCCAACGACCTGGGCAAAAACACCAGCATCCTCTTCCTGGAGCTGGTCAATTTAACCACCCTCACACCAGACTCCAACACAACCACTGGCCTCAGCACTTCCACTGCCAGTCCTCATACCAGAGCCAACAGCACCTCCACAGAGAGAAAGCTGCCGGAG SEQ ID NO: 13(soluble CD146)ATGGGGCTTCCCAGGCTGGTCTGCGCCTTCTTGCTCGCCGCCTGCTGCTGCTGTCCTCGCGTCGCGGGTGTGCCCGGAGAGGCTGAGCAGCCTGCGCCTGAGCTGGTGGAGGTGGAAGTGGGCAGCACAGCCCTTCTGAAGTGCGGCCTCTCCCAGTCCCAAGGCAACCTCAGCCATGTCGACTGGTTTTCTGTCCACAAGGAGAAGCGGACGCTCATCTTCCGTGTGCGCCAGGGCCAGGGCCAGAGCGAACCTGGGGAGTACGAGCAGCGGCTCAGCCTCCAGGACAGAGGGGCTACTCTGGCCCTGACTCAAGTCACCCCCCAAGACGAGCGCATCTTCTTGTGCCAGGGCAAGCGCCCTCGGTCCCAGGAGTACCGCATCCAGCTCCGCGTCTACAAAGCTCCGGAGGAGCCAAACATCCAGGTCAACCCCCTGGGCATCCCTGTGAACAGTAAGGAGCCTGAGGAGGTCGCTACCTGTGTAGGGAGGAACGGGTACCCCATTCCTCAAGTCATCTGGTACAAGAATGGCCGGCCTCTGAAGGAGGAGAAGAACCGGGTCCACATTCAGTCGTCCCAGACTGTGGAGTCGAGTGGTTTGTACACCTTGCAGAGTATTCTGAAGGCACAGCTGGTTAAAGAAGACAAAGATGCCCAGTTTTACTGTGAGCTCAACTACCGGCTGCCCAGTGGGAACCACATGAAGGAGTCCAGGGAAGTCACCGTCCCTGTTTTCTACCCGACAGAAAAAGTGTGGCTGGAAGTGGAGCCCGTGGGAATGCTGAAGGAAGGGGACCGCGTGGAAATCAGGTGTTTGGCTGATGGCAACCCTCCACCACACTTCAGCATCAGCAAGCAGAACCCCAGCACCAGGGAGGCAGAGGAAGAGACAACCAACGACAACGGGGTCCTGGTGCTGGAGCCTGCCCGGAAGGAACACAGTGGGCGCTATGAATGTCAGGGCCTGGACTTGGACACCATGATATCGCTGCTGAGTGAACCACAGGAACTACTGGTGAACTATGTGTCTGACGTCCGAGTGAGTCCCGCAGCCCCTGAGAGACAGGAAGGCAGCAGCCTCACCCTGACCTGTGAGGCAGAGAGTAGCCAGGACCTCGAGTTCCAGTGGCTGAGAGAAGAGACAGGCCAGGTGCTGGAAAGGGGGCCTGTGCTTCAGTTGCATGACCTGAAACGGGAGGCAGGAGGCGGCTATCGCTGCGTGGCGTCTGTGCCCAGCATACCCGGCCTGAACCGCACACAGCTGGTCAACGTGGCCATTTTTGGCCCCCCTTGGATGGCATTCAAGGAGAGGAAGGTGTGGGTGAAAGAGAATATGGTGTTGAATCTGTCTTGTGAAGCGTCAGGGCACCCCCGGCCCACCATCTCCTGGAACGTCAACGGCACGGCAAGTGAACAAGACCAAGATCCACAGCGAGTCCTGAGCACCCTGAATGTCCTCGTGACCCCGGAGCTGTTGGAGACAGGTGTTGAATGCACGGCCTCCAACGACCTGGGCAAAAACACCAGCATCCTCTTCCTGGAGCTGGTCAATTTAACCACCCTCACACCAGACTCCAACACAACCACTGGCCTCAGCACTTCCACTGCCAGTCCTCATACCAGAGCCAACAGCACCTCCACAGAGAGAAAGCTGCCGGAGCCG SEQ ID NO: 14(soluble CD146)ATGGGGCTTCCCAGGCTGGTCTGCGCCTTCTTGCTCGCCGCCTGCTGCTGCTGTCCTCGCGTCGCGGGTGTGCCCGGAGAGGCTGAGCAGCCTGCGCCTGAGCTGGTGGAGGTGGAAGTGGGCAGCACAGCCCTTCTGAAGTGCGGCCTCTCCCAGTCCCAAGGCAACCTCAGCCATGTCGACTGGTTTTCTGTCCACAAGGAGAAGCGGACGCTCATCTTCCGTGTGCGCCAGGGCCAGGGCCAGAGCGAACCTGGGGAGTACGAGCAGCGGCTCAGCCTCCAGGACAGAGGGGCTACTCTGGCCCTGACTCAAGTCACCCCCCAAGACGAGCGCATCTTCTTGTGCCAGGGCAAGCGCCCTCGGTCCCAGGAGTACCGCATCCAGCTCCGCGTCTACAAAGCTCCGGAGGAGCCAAACATCCAGGTCAACCCCCTGGGCATCCCTGTGAACAGTAAGGAGCCTGAGGAGGTCGCTACCTGTGTAGGGAGGAACGGGTACCCCATTCCTCAAGTCATCTGGTACAAGAATGGCCGGCCTCTGAAGGAGGAGAAGAACCGGGTCCACATTCAGTCGTCCCAGACTGTGGAGTCGAGTGGTTTGTACACCTTGCAGAGTATTCTGAAGGCACAGCTGGTTAAAGAAGACAAAGATGCCCAGTTTTACTGTGAGCTCAACTACCGGCTGCCCAGTGGGAACCACATGAAGGAGTCCAGGGAAGTCACCGTCCCTGTTTTCTACCCGACAGAAAAAGTGTGGCTGGAAGTGGAGCCCGTGGGAATGCTGAAGGAAGGGGACCGCGTGGAAATCAGGTGTTTGGCTGATGGCAACCCTCCACCACACTTCAGCATCAGCAAGCAGAACCCCAGCACCAGGGAGGCAGAGGAAGAGACAACCAACGACAACGGGGTCCTGGTGCTGGAGCCTGCCCGGAAGGAACACAGTGGGCGCTATGAATGTCAGGGCCTGGACTTGGACACCATGATATCGCTGCTGAGTGAACCACAGGAACTACTGGTGAACTATGTGTCTGACGTCCGAGTGAGTCCCGCAGCCCCTGAGAGACAGGAAGGCAGCAGCCTCACCCTGACCTGTGAGGCAGAGAGTAGCCAGGACCTCGAGTTCCAGTGGCTGAGAGAAGAGACAGGCCAGGTGCTGGAAAGGGGGCCTGTGCTTCAGTTGCATGACCTGAAACGGGAGGCAGGAGGCGGCTATCGCTGCGTGGCGTCTGTGCCCAGCATACCCGGCCTGAACCGCACACAGCTGGTCAACGTGGCCATTTTTGGCCCCCCTTGGATGGCATTCAAGGAGAGGAAGGTGTGGGTGAAAGAGAATATGGTGTTGAATCTGTCTTGTGAAGCGTCAGGGCACCCCCGGCCCACCATCTCCTGGAACGTCAACGGCACGGCAAGTGAACAAGACCAAGATCCACAGCGAGTCCTGAGCACCCTGAATGTCCTCGTGACCCCGGAGCTGTTGGAGACAGGTGTTGAATGCACGGCCTCCAACGACCTGGGCAAAAACACCAGCATCCTCTTCCTGGAGCTGGTCAATTTAACCACCCTCACACCAGACTCCAACACAACCACTGGCCTCAGCACTTCCACTGCCAGTCCTCATACCAGAGCCAACAGCACCTCCACAGAGAGAAAGCTGCCGGAGCCGGAG SEQ ID NO: 15(soluble CD146)ATGGGGCTTCCCAGGCTGGTCTGCGCCTTCTTGCTCGCCGCCTGCTGCTGCTGTCCTCGCGTCGCGGGTGTGCCCGGAGAGGCTGAGCAGCCTGCGCCTGAGCTGGTGGAGGTGGAAGTGGGCAGCACAGCCCTTCTGAAGTGCGGCCTCTCCCAGTCCCAAGGCAACCTCAGCCATGTCGACTGGTTTTCTGTCCACAAGGAGAAGCGGACGCTCATCTTCCGTGTGCGCCAGGGCCAGGGCCAGAGCGAACCTGGGGAGTACGAGCAGCGGCTCAGCCTCCAGGACAGAGGGGCTACTCTGGCCCTGACTCAAGTCACCCCCCAAGACGAGCGCATCTTCTTGTGCCAGGGCAAGCGCCCTCGGTCCCAGGAGTACCGCATCCAGCTCCGCGTCTACAAAGCTCCGGAGGAGCCAAACATCCAGGTCAACCCCCTGGGCATCCCTGTGAACAGTAAGGAGCCTGAGGAGGTCGCTACCTGTGTAGGGAGGAACGGGTACCCCATTCCTCAAGTCATCTGGTACAAGAATGGCCGGCCTCTGAAGGAGGAGAAGAACCGGGTCCACATTCAGTCGTCCCAGACTGTGGAGTCGAGTGGTTTGTACACCTTGCAGAGTATTCTGAAGGCACAGCTGGTTAAAGAAGACAAAGATGCCCAGTTTTACTGTGAGCTCAACTACCGGCTGCCCAGTGGGAACCACATGAAGGAGTCCAGGGAAGTCACCGTCCCTGTTTTCTACCCGACAGAAAAAGTGTGGCTGGAAGTGGAGCCCGTGGGAATGCTGAAGGAAGGGGACCGCGTGGAAATCAGGTGTTTGGCTGATGGCAACCCTCCACCACACTTCAGCATCAGCAAGCAGAACCCCAGCACCAGGGAGGCAGAGGAAGAGACAACCAACGACAACGGGGTCCTGGTGCTGGAGCCTGCCCGGAAGGAACACAGTGGGCGCTATGAATGTCAGGGCCTGGACTTGGACACCATGATATCGCTGCTGAGTGAACCACAGGAACTACTGGTGAACTATGTGTCTGACGTCCGAGTGAGTCCCGCAGCCCCTGAGAGACAGGAAGGCAGCAGCCTCACCCTGACCTGTGAGGCAGAGAGTAGCCAGGACCTCGAGTTCCAGTGGCTGAGAGAAGAGACAGGCCAGGTGCTGGAAAGGGGGCCTGTGCTTCAGTTGCATGACCTGAAACGGGAGGCAGGAGGCGGCTATCGCTGCGTGGCGTCTGTGCCCAGCATACCCGGCCTGAACCGCACACAGCTGGTCAACGTGGCCATTTTTGGCCCCCCTTGGATGGCATTCAAGGAGAGGAAGGTGTGGGTGAAAGAGAATATGGTGTTGAATCTGTCTTGTGAAGCGTCAGGGCACCCCCGGCCCACCATCTCCTGGAACGTCAACGGCACGGCAAGTGAACAAGACCAAGATCCACAGCGAGTCCTGAGCACCCTGAATGTCCTCGTGACCCCGGAGCTGTTGGAGACAGGTGTTGAATGCACGGCCTCCAACGACCTGGGCAAAAACACCAGCATCCTCTTCCTGGAGCTGGTCAATTTAACCACCCTCACACCAGACTCCAACACAACCACTGGCCTCAGCACTTCCACTGCCAGTCCTCATACCAGAGCCAACAGCACCTCCACAGAGAGAAAGCTGCCGGAGCCGGAGAGC SEQ ID NO: 16(soluble CD146)ATGGGGCTTCCCAGGCTGGTCTGCGCCTTCTTGCTCGCCGCCTGCTGCTGCTGTCCTCGCGTCGCGGGTGTGCCCGGAGAGGCTGAGCAGCCTGCGCCTGAGCTGGTGGAGGTGGAAGTGGGCAGCACAGCCCTTCTGAAGTGCGGCCTCTCCCAGTCCCAAGGCAACCTCAGCCATGTCGACTGGTTTTCTGTCCACAAGGAGAAGCGGACGCTCATCTTCCGTGTGCGCCAGGGCCAGGGCCAGAGCGAACCTGGGGAGTACGAGCAGCGGCTCAGCCTCCAGGACAGAGGGGCTACTCTGGCCCTGACTCAAGTCACCCCCCAAGACGAGCGCATCTTCTTGTGCCAGGGCAAGCGCCCTCGGTCCCAGGAGTACCGCATCCAGCTCCGCGTCTACAAAGCTCCGGAGGAGCCAAACATCCAGGTCAACCCCCTGGGCATCCCTGTGAACAGTAAGGAGCCTGAGGAGGTCGCTACCTGTGTAGGGAGGAACGGGTACCCCATTCCTCAAGTCATCTGGTACAAGAATGGCCGGCCTCTGAAGGAGGAGAAGAACCGGGTCCACATTCAGTCGTCCCAGACTGTGGAGTCGAGTGGTTTGTACACCTTGCAGAGTATTCTGAAGGCACAGCTGGTTAAAGAAGACAAAGATGCCCAGTTTTACTGTGAGCTCAACTACCGGCTGCCCAGTGGGAACCACATGAAGGAGTCCAGGGAAGTCACCGTCCCTGTTTTCTACCCGACAGAAAAAGTGTGGCTGGAAGTGGAGCCCGTGGGAATGCTGAAGGAAGGGGACCGCGTGGAAATCAGGTGTTTGGCTGATGGCAACCCTCCACCACACTTCAGCATCAGCAAGCAGAACCCCAGCACCAGGGAGGCAGAGGAAGAGACAACCAACGACAACGGGGTCCTGGTGCTGGAGCCTGCCCGGAAGGAACACAGTGGGCGCTATGAATGTCAGGGCCTGGACTTGGACACCATGATATCGCTGCTGAGTGAACCACAGGAACTACTGGTGAACTATGTGTCTGACGTCCGAGTGAGTCCCGCAGCCCCTGAGAGACAGGAAGGCAGCAGCCTCACCCTGACCTGTGAGGCAGAGAGTAGCCAGGACCTCGAGTTCCAGTGGCTGAGAGAAGAGACAGGCCAGGTGCTGGAAAGGGGGCCTGTGCTTCAGTTGCATGACCTGAAACGGGAGGCAGGAGGCGGCTATCGCTGCGTGGCGTCTGTGCCCAGCATACCCGGCCTGAACCGCACACAGCTGGTCAACGTGGCCATTTTTGGCCCCCCTTGGATGGCATTCAAGGAGAGGAAGGTGTGGGTGAAAGAGAATATGGTGTTGAATCTGTCTTGTGAAGCGTCAGGGCACCCCCGGCCCACCATCTCCTGGAACGTCAACGGCACGGCAAGTGAACAAGACCAAGATCCACAGCGAGTCCTGAGCACCCTGAATGTCCTCGTGACCCCGGAGCTGTTGGAGACAGGTGTTGAATGCACGGCCTCCAACGACCTGGGCAAAAACACCAGCATCCTCTTCCTGGAGCTGGTCAATTTAACCACCCTCACACCAGACTCCAACACAACCACTGGCCTCAGCACTTCCACTGCCAGTCCTCATACCAGAGCCAACAGCACCTCCACAGAGAGAAAGCTGCCGGAGCCGGAGAGCCG G

The natural (non recombinant) molecules may be isolated, for examplefrom a nucleic acid library prepared from a tissue known to express thedesired protein, e.g., blood, in particular serum or bone marrow, thelibrary being screened with an appropriate probe, or from a tissuesample (bone marrow, blood, serum, etc.), preferably a sample of thesubject to be treated (see for example Hoskins R A, Stapleton M, GeorgeR A, Yu C, Wan K H, Carlson J W, Celniker S E. Rapid and efficient cDNAlibrary screening by self-ligation of inverse PCR products (SLIP).Nucleic Acids Research 2005; 33:185-197).

The nucleic acid molecules may otherwise be artificially produced, forexample by oligonucleotides synthesis (see for example Michaels M L,Hsiao H M, Miller J H. Using PCR to extend the limit of oligonucleotidesynthesis. Biotechniques. 1992; 12:44- 48).

A preferred human soluble CD146 protein according to the presentinvention may be obtained using a method comprising the following stepsof transfecting a mammalian cell with an appropriate vector expressing ahuman soluble CD146 protein and isolating the expressed human CD 146protein.

Herein described is a recombinant human soluble CD146 (rh-sCD146)protein fused to another polypeptide, such as a tag polypeptide sequence(see the c-myc tagged human soluble CD 146 in the experimental partwherein the sequence of the soluble CD146 is SEQ ID NO: 7).

The nucleic acid molecule can be provided in a replicable vectorcomprising the nucleic acid molecule operably linked to controlsequences recognized by a host cell transfected or transformed with thevector, in particular a mature or immature endothelial cell or aprogenitor cell, preferably an endothelial progenitor cell (EPC, alsoherein identified as EPDC), typically a cell as previously hereindescribed. The invention further provides such an host cell comprisingthe vector or the nucleic acid molecule as further explained below.

The amino acid molecules of the present invention can be designed to becompatible with a diagnostic, therapeutic or prophylactic use in amammal, preferably a human. They can be, for example, glycosylated,methylated, acetylated, phosphorylated, for targeting different types oftissues, in particular a pathological tissue such as, typically, anischemic tissue, preferably in a human.

Suitable host cells for the expression of glycosylated soluble humanCD146 may be selected from mammalian cell lines, for example CHO cells.

In another embodiment, the invention provides a composition, inparticular a pharmaceutical composition useful for promotion of vascularcell growth, typically endothelial cell growth, comprising, preferablyin a therapeutically effective amount, a soluble CD146 protein, asherein described, in a pharmaceutically acceptable carrier or excipient.

A “therapeutically affective amount” of a soluble CD146 protein is anamount allowing the treatment, as previously defined, of a mammal.

A pharmaceutically acceptable excipient, vehicle or carrier, usable inthe context of the present invention, is for example a saline, isotonic,buffered solution such as Mannitol 20%, optionally combined withstabilizing agents such as isogenic albumin or any other stabilizingprotein, glycerol, etc., and also adjuvants such as polybrene or DEAEdextrans, etc.

In a particular aspect, the herein described compositions comprising asoluble CD46, preferably a human soluble CD146 may further comprise atleast one other angiogenic factor.

In the context of the present invention an angiogenic factor is a factorwhich favors blood vessel development.

Angiogenic factors usable in the context of the present invention may beselected from angiogenin, angiopoietin-1, Del-1, fibroblast growthfactors: acidic (aFGF) and basic (bFGF), follistatin, granulocytecolony-stimulating factor (G-CSF), granulocyte-macrophage colonystimulating factor (GM-CSF), stem cell factor (SCF), hepatocyte growthfactor (HGF)/scatter factor (SF), interleukin-8 (IL-8), leptin, midkine,placental growth factor, platelet-derived endothelial cell growth factor(PD-ECGF), platelet-derived growth factor-BB (PDGF-BB), pleiotrophin(PTN), erytropoietin (EPO), endothelial nitric oxyd synthase (e-NOS),progranulin, proliferin, transforming growth factor-alpha (TGF-alpha),transforming growth factor-beta (TGF-beta), tumor necrosis factor-alpha(TNF-alpha), vascular endothelial growth factor (VEGF), vascularpermeability factor (VPF), Angiopoietin-1 (Ang1), plasminogen activatorurokinase (PLAU/u-Pa), the matrix metallopeptidase MMP-2, the VEGFreceptor 2 (KDR), stromal-cell-derived-factor-1 (SDF-1), etc., and amixture thereof.

Preferred angiogenic factors may be selected from vascular endothelialgrowth factor (VEGF—see experimental section and FIG. 5),stromal-cell-derived-factor-1 (SDF-1), basic fibroblast growth factors(bFGF), erytropoietin (EPO), granulocyte colony-stimulating factor(G-CSF), granulocyte-macrophage colony stimulating factor (GM-CSF), stemcell factor (SCF), interleukin-8 (IL-8) and a mixture thereof.

In another particular aspect, the herein described compositionscomprising an antibody directed against a soluble CD146 may furthercomprise at least one other antibody directed against one of thepreviously identified angiogenic factor.

In another particular aspect, the herein described compositionscomprising a human soluble CD146 may in addition comprise a mature orimmature endothelial cell or a progenitor cell, typically of humanorigin, preferably in vitro-expanded progenitor cells, in particularstem cells or endothelial progenitor cells, typically cells derived fromblood or bone marrow, for example selected from cells expressing CD34,CD133, CD31, VE-cadherin, VEGFR2, c-Kit, CD45 and/or Tie-2.

Compositions comprising cells as previously mentioned contacted with asoluble CD146 as herein defined before being optionally incorporated ina pharmaceutically acceptable excipient are an embodiment of the presentinvention as further explained below. Such compositions do not compriseadded soluble CD 146.

In a preferred embodiment, the progenitor cell is a recombinantprogenitor cell. Such a recombinant cell may be genetically modifiedusing an appropriate vector comprising or consisting in a genetic ornucleic acid construct expressing, preferably enabling an overexpressionof, a particular biologically active form of CD146, preferably of thehuman short form of CD146 or human soluble form of CD146, as definedpreviously.

Many vectors are available. Preferred vectors may be selected from aplasmid, a retrovirus, a lentivirus and an adenovirus. The vectorcomponents generally include, but are not limited to, one or more of thefollowing: a signal sequence, an origin of replication, one or moremarker genes, an enhancer element, a promoter, and a transcriptiontermination sequence, easily selectable by the man of the art (see forexample Liu J W, Pernod G, Dunoyer-Geindre S, Fish R J, Yang H,Bounameaux H, Kruithof E K. Promoter dependence of transgene expressionby lentivirus-transduced human blood-derived endothelial progenitorcells. Stem Cells. 2006; 24:199-208).

Such a progenitor cell may be transfected with the appropriate vector,preferably with a plasmid as described previously, according to knownprotocols, preferably a protocol appropriate to endothelial progenitorcells such as electroporation or use of liposomes, and then cultured inany known suitable media (a medium comprising EGM-2 for example),optionally supplemented with one or more of the following: anappropriate hormone, growth factor, buffer, etc. The progenitor cellsmay then be expanded in vitro using any method known by the man of theart (see for example Delorme B et al. Presence of endothelial progenitorcells, distinct from mature endothelial cells, within human CD146+ bloodcells. Thromb Haemost. 2005 ;94:1270-9).

Also incorporated in the present invention is the use of a human solubleCD146 protein according to the invention to prepare, ex vivo, a matureor immature endothelial cell or a progenitor cell, as previouslydefined, exhibiting therapeutic or prophylactic properties, inparticular capable of stimulating angiogenesis in a human body.Inventors have indeed discovered that such cells contacted,“pre-treated” or “primed” with a human soluble CD146 protein accordingto the invention are able by themselves, once administered to a subject,to induce or stimulate vasculogenesis and/or angiogenesis. The“pre-treated” or “primed” cells have been contacted with, or cultured inthe presence of, a human soluble CD146 protein according to theinvention before being optionally incorporated into a pharmaceuticallyacceptable support.

Such cells are further object of the present invention as well as thepharmaceutical compositions comprising said cells, preferably in apharmaceutically acceptable support. While preparing such pharmaceuticalcompositions further adding human soluble CD146 is optional.

Preferred “pre-treated” or “primed” cells are cells which have beengenetically modified, as explained previously, to overexpress the shortform of CD146 or soluble CD146.

In a further aspect, the invention relates to a protein or a compositionas herein described for use in the treatment of a disease, disorder ordysfunctional state leading to tissue ischemia or characterized by adecreased activation of a receptor for CD146, in particular solubleCD146, or by a decreased expression of a gene selected from the geneencoding e-NOS, uPa, MMP-2 and KDR, compared to standard values.

The invention relates to a protein or a composition as herein describedfor use in the prevention of ischemia.

In particular, the invention relates to the use of a protein or acomposition as herein described to prepare a composition for preventingor treating a disease, a disorder or a dysfunctional state as hereinpreviously identified.

In another particular embodiment, the invention provides a method ofpreventing or treating a disease, a disorder or a dysfunctional state ina mammal, preferably a human, as herein identified, in particular amethod of preventing or treating a tissue ischemia, comprisingadministering to the mammal, an effective amount of a composition, asherein described, comprising a soluble CD146 protein.

In a further aspect, the invention relates to the use of a protein or acomposition as herein described to improve the aesthetic appearance of ascar or, in prevention, to facilitate the cicatrization or healing of awound, a cut or an incision.

An object of the present invention is a protein or a composition asherein described for use in the cicatrization of a mammal epithelium, inparticular a human epithelium, in particular following a wound, a cut oran incision, or in the context of a skin graft.

Another object of the present invention is a protein or a composition asherein described for use in the prevention or treatment of an eschar ora bedsore in a mammal, in particular a human.

Preferred compositions for use in the context of cicatrisation will beadvantageously formulated for topic application according to methodsknown by the man of the art.

In another embodiment, the present invention further provide amonoclonal antibody which selectively binds to a human soluble CD146protein according to the present invention, preferably to the proteincomprising an amino acid sequence consisting in SEQ ID NO: 1 or SEQ NO:6.

This antibody preferably also neutralizes a biological activity of thehuman soluble CD146 protein of the invention. Preferably, the monoclonalantibody decreases or inhibits neovascularization, vascular permeabilityand/or vascular endothelial cell growth in a subject as herein defined,typically a mammal, preferably a human.

The monoclonal antibody is also preferably able to reduce or suppress anexcessive expression (compared to a standard expression) of a solubleCD146 receptor, or an excessive expression (compared to a standardexpression) of a gene selected from the gene encoding e-NOS, uPa, MMP-2and KDR.

Antibodies binding both the human soluble CD146 protein and a CD146 orsoluble CD146 protein receptor (or a CD146 protein receptor subunit) arealso within the scope of the present invention. Methods of making suchantibodies are known in the art (See for example Despoix N, Walzer T,Jouve N, Blot-Chabaud M, Bardin N, Paul P, Lyonnet L, Vivier E,Dignat-George F, Vély F. Mouse CD146/MCAM is a marker of natural killercell maturation. Eur J Immunol. 2008;38: 2855-64).

Preferred antibodies selected by inventors in the context of the presentinvention, capable of selectively binding soluble CD146 (versus membraneCD146), are identified on FIG. 7 (2B9-4, 2B9-5, 26D12-6, 26D12-7,26D12-8 and 15E8-1).

The herein described antibodies may be incorporated into a compositionfurther comprising a pharmaceutically acceptable carrier, in respectiveappropriate dosages.

In a particular aspect, the herein described compositions comprising anantibody as herein described, in particular an antibody specificallydirected against the human soluble CD146 herein described whichpreferably consists in SEQ ID NO: 1 or SEQ ID NO: 6, may furthercomprise at least one other anti-angiogenic factor. In the context ofthe present invention an anti-angiogenic factor is a factor whichinhibits or interferes with blood vessel development. Anti-angiogenicfactors usable in the context of the present invention may be selectedfrom an antibody directed against an angiogenic factor as previouslydefined, angioarrestin, angiostatin (plasminogen fragment),antiangiogenic antithrombin III, cartilage-derived inhibitor (CDT), CD59complement fragment, endostatin (collagen XVIII fragment), fibronectinfragment, gro-beta, an heparinase, heparin hexasaccharide fragment,human chorionic gonadotropin (hCG), interferon alpha/beta/gamma,Interferon inducible protein (IP-10), interleukin-12, kringle 5(plasminogen fragment), metalloproteinase inhibitors (TIMPs),2-Methoxyestradiol, placental ribonuclease inhibitor, plasminogenactivator inhibitor, platelet factor-4 (PF4), prolactin 16kD fragment,proliferin-related protein (PRP), a retinoid, tetrahydrocortisol-S,thrombospondin-1 (TSP-1), transforming growth factor-beta (TGF-b),vasculostatin, vasostatin (calreticulin fragment), etc., and a mixturethereof.

The antibody, or a pharmaceutical composition comprising at least saidantibody and a pharmaceutically acceptable carrier, herein disclosed,can be used in a mammal, preferably a human, for preventing or treatinga disease, disorder or dysfunctional state characterized by anundesirable excessive neovascularization or vascular permeability, suchas a cancer, in particular a breast cancer or a melanoma, or by anoverexpression or excessive activation of a receptor for CD146, inparticular soluble CD146, or by an excessive expression of a geneselected from the gene encoding e-NOS, uPa, MMP-2 and KDR, compared tostandard expressions.

The doses of the diagnostic or pharmaceutical composition may beadjusted by the skilled person depending on the treated subject, theroute of administration, the targeted tissue, the biologically activecompound (as herein disclosed), etc.

Various protocols may be used for the administration, such assimultaneous or sequential administration of the human soluble CD146 andof any other compound as defined previously (“pre-treated”, “primed”,and/or genetically modified cells as described previously for example),single or repeated administration, etc., which may be adjusted by theskilled person.

The pharmaceutical composition containing the product according to theinvention may be administered to a patient for example systemically,subcutaneously, intraspinally or intracerebrally, given the targetedpathological tissue or area. Preferred modes of injection are systemicalinjections, in particular intra-venous or intra-arterial injections, orsubcutaneous injections.

The molecules of the present invention may further be used in methods ofdiagnostic. The term diagnostic designates any in vivo, ex vivo or invitro diagnosis, including molecule detection, monitoring,quantification, comparison, etc. In particular, the human soluble CD146protein may be used as a biomarker providing an indication of thepresence of a disease in a mammal, preferably a human, in particular anischemia or a cancer, of metastasis of a tumor, or of the evolution ofsuch a diseased state. In particular the serum concentration of thehuman soluble CD146 protein may be an indication of high value in thisregards. The measured value may be indeed compared to standard valuesassociated to a healthy status of a subject. An overexpression of thesoluble form of CD146 may be, in particular, indicative of the presenceof a cancer.

The term diagnosis also includes the use of the molecules to screencompounds or treatments that cause or increase apoptosis of a cell, invitro, ex vivo or in vivo.

Also herein provided is a kit comprising at least one biologicallyactive product as herein described, such as a human soluble CD146, anantibody, in particular a monoclonal antibody, directed against saidhuman soluble CD146, a “pre-treated” or “primed” (stimulated by saidhuman soluble CD146) and/or genetically modified (to overexpress theshort form of CD146 or soluble CD146) cell, and optionally (ii) aleaflet providing guidelines.

Further aspects and advantages of the present invention will bedescribed in the following examples, which should be regarded asillustrative and not limiting. All references cited in the presentapplication are herein incorporated by reference.

EXAMPLES Example 1 Soluble CD146 Displays Angiogenic Properties andPromotes Neovascularisation in Experimental Hind Limb Ischemia

Materials and Methods

Recombinant Human Soluble CD146

A c-myc tagged recombinant protein corresponding to the soluble form ofhuman CD146 was obtained from Biocytex (Marseille, France). Epitopetagging of CD146 at its N-terminus enabled us to detect specifically therecombinant molecule using an anti- c-myc peptide antibody (Abeam) andto distinguish it from endogenous CD146.

Matrigel Plugs in Vivo

Non immunocompromised or nude mice were anesthetized and 400 μl ice-coldmatrigel, containing either 0.1 μg/μl c-myc peptide or 0.1 μg/μlrh-sCD146, were injected respectively into the left and right groin areaof each animal Animals were then injected or not with 500,000 late EPCdepending on the experiment. After 12 days, the matrigel plugs wereremoved and frozen. Procedures described above were conducted under aninstitutional approved animal use protocol.

Induction of Hind Limb Ischemia in Rats

Male rats were subjected to unilateral hind limb ischemia by completeresection of the entire left femoral artery followed by microbeadsinjection. Laser-doppler tissue imaging showed that obstruction of theleft common femoral artery decreased blood perfusion by about 90% atday 1. After surgery, animals were split in four treatment groups: twocontrol groups injected daily in ischemic adductor muscles with 10 μgc-myc peptide for either 5 or 12 days; two experimental groups treatedas the control groups except that the c-myc peptide was replaced withrecombinant human soluble CD146 (rh-sCD146). The procedures describedabove were conducted under an institutional approved animal useprotocol.

Laser Doppler Blood Flow Analysis

The ratio of the ischemic vs. normal hind limb blood flow was measuredusing a laser Doppler blood flow analyzer. At different time points(postoperative days 1, 5, 10, 15 and 21), animals were subjected to 2consecutive laser scannings over the regions of interest (leg and feet).Blood flow was expressed as the ischemic vs. normal hind limb ratio.

Morphological, Histological and Immunochemical Assessment.

At day 20 after ischemia induction or initiation, animals weresacrificed with a lethal dose of pentobarbital (Clin Midy, Gentilly,France) and muscles were fixed by trans-cardiac perfusion with 4%phosphate-buffered paraformaldehyde (Sigma-Aldrich). Frozen sectionswere cut with a sliding microtome (CM1900, Leica, France SA) and storedat −20° C. All sections were examined by investigators blind to theexperimental conditions using a light microscope (Eclipse TE 2000-U,Nikon France SA) equipped with a digital camera (DXM1200, Nikon FranceSA).

Histological analysis was performed 20 days after ischemia induction bymicroscopic examination of the cell changes induced in the core and inthe boundary zone of the ischemic area, on serial muscle sectionsstained with eosin-hematoxylin. Sections were examined under lightmicroscope on two consecutive sections. A semi-quantitative evaluationof the cell changes was performed using a four-point scale from absence(−) to intense (++). Capillary density was determined by microscopicanalysis of muscle cryosections.

In in vivo matrigel plugs experiments or experiments on muscles, 5μm-thick sections were used for staining. After blocking in normalserum, the sections were treated overnight at 4° C. with anti-CD31(1/50), anti-CD117 (1/50), anti-CD34 (1/40), anti-CD45 (1/200) antibody,anti-MOMA2 antibody (1/200), anti-αsma antibody (1/80), anti-CD33antibody (1/100), or anti-CD146 antibody (1/100). Signal amplificationutilized fluorochrome (Alexa 488 or Alexa 647)-conjugated secondaryantibodies (1/250; Invitrogen) when non-coupled. Sections werecounterstained with DAPI (1:1000, Sigma-Aldrich), rinsed and mounted.For the assessment of non-specific staining, alternating sections wereincubated without the primary antibody.

Isolation of Circulating Progenitor Endothelial Cells and Cell Culture

Human umbilical cord blood samples harvested from donors after consentwere collected in a heparinized tube. Mononuclear cells (MNC) wereisolated by density gradient centrifugation. Cord blood MNC were thenpre-plated in RPMI/10% fetal calf serum (FCS) for 24 hours in plasticflasks. Non adherent cells were plated onto 0.2% gelatin-coated 24-wellplates (10⁵ cells per well) and maintained in endothelial basal medium-2(EBM-2) supplemented with EGM-2 SingleQuots (EGM-2 medium, Clonetics,Walkersville, Md., USA). For expansion of endothelial progenitor derivedcells (EPDC), also called late endothelial progenitor cells (EPC),colonies were trypsinized and cells were replated on plates or labtekslides depending on the experiment. Cells were maintained under standardconditions (humidified atmosphere, 5% CO₂, 37° C.).

For EPDC stimulation experiments, cells were maintained for 3 hours inEBM2 and then stimulated with 50 ng/ml of recombinant human solubleCD146 (rh-sCD146) (biocytex), 20 ng/ml VEGF (R&D systems, Minneapolis,Minn., USA) or the appropriate solution for 1 to 24 hours, depending onthe experiment.

Chemotactic Activity in vitro

Experiments were performed on semi-permeable Transwell filters (8 mporosity; 24 wells; B&D) in EGM2 medium. 500,000 EPDC previouslylabelled for 30 min at 37° C. with calcein were seeded in the uppercompartment. Different concentrations of rh-sCD146 were then added inthe lower compartment and migration of EPDC across the filter wasmeasured after an overnight incubation at 37° C. Fluorescence intensitywas measured using a cytofluor apparatus (Cytofluor Series 4000;PerSeptive Biosystems).

Endothelial Cell Tube Formation in Matrigel

96-well plates were pre-coated with 1:1 mixture of cold Matrigel™Basement Membrane (10 mg/ml, BD Biosciences, Bedford, Mass., USA): EBM-2medium. After 45 minutes of polymerization at 37° C., EPDC were platedat 10⁴ cells/well in EBM supplemented or not with rh-sCD146 or VEGF.After 5 hours, pictures of representative fields were taken for eachcondition under an inverted microscope at 400× magnification. Capillarytube formation was evaluated by measuring the total tube length and thenumber of tubes per field with the Lucia® software (Nikon).

Cell Proliferation Assay

EPDC were seeded on 96-well plates (5.10³/well) and cultured in EGM-2medium for 3 days. Cells were then preincubated for 2 hours in EBM-2medium. Cell proliferation was assayed by 5-bromo-2′-deoxy-uridine(BrdU) incorporation into cellular DNA using the BrdU Labeling andDetection Kit III from Roche Corporation. In brief, cells were incubated12 hours with BrdU labeling solution in EBM-2 medium in the absence orpresence of rh-sCD146 or VEGF. Cellular DNA was partially digested bynuclease treatment and incorporated BrdU was detected withperoxidase-conjugated primary antibodies. The absorbance was measured at405 nm using a Uvmc2 micro-plate reader (Safas, Monaco). Results wereexpressed as arbitrary units. Experiments were performed in triplicates.

Wound Healing Assay

A reproducible wound was made with a pipet tip on a confluent monolayerof EPDC cultured on 24-well plates. The surface of the wound wasmeasured at 400× magnification using an Olympus inverted microscope andacquired with the Biocom Visiolab image analysis software (Les Ulis,France). The medium was removed and EPDC were incubated for 6 hours withEBM-2 containing or not different concentrations of rh-sCD146. Cellwound repair was calculated by subtracting the wound area measured after6 hours of incubation from the area of the original wound. Results wereexpressed as a percentage of the area of the original wound, consideredas 100%.

Western-blot Analysis

Western-blot analysis was performed as followed. Briefly, cells weregrown on plates treated or not with rh-sCD146, then washed in PBS,scraped off the plates and extracted with 300 μl of ice-cold lysisbuffer (150 mM NaCl,50 mM Tris HCl (pH 7.4), 2.4 mM EDTA, 1% NonidetP40, 0.5 mM phenylmethylsulfonyl fluoride) for 30 min at 4° C. Aftercentrifugation (12,000 g, 10 min, 4° C.) to eliminate cell debris andnuclei, proteins were quantified by protein assay (Biorad). 30 g ofprotein were resuspended in 40 μl of NuPage LDS sample Buffer(Invitrogen). Samples were then submitted to 4-12% NuPageSDS-polyacrylamide gel electrophoresis (Invitrogen) and transferred ontonitrocellulose membrane (Invitrogen). Membranes were probed withspecific primary antibodies (anti-KDR, anti uPa, anti-MMP-2, anti e-NOS(see below)) followed by secondary antibodies coupled to peroxidase andrevealed with the ECL kit (Amersham). Membranes we probed with variousantibodies after stripping.

Gene Expression Profiling

Total cellular RNA was isolated from cultured EPDC treated or not for 3hours with 50 ng/ml rh-sCD146. This was performed using the RNeasy Kit(Qiagen GmbH, Hilden, Germany) according to the manufacturer'sinstructions including the DNase digestion step. Oligoarrayhybridizations were performed according to the manufacturer usingangiogenesis oligoarrays (Tebu-Bio). Spots were quantified using theTebu-Bio software. Subtraction of background was done for the signalmean intensities in both test and reference DNA spots. Normalization inthe calculated ratios was done against the average of all ratios. Thehybridizations were performed three times and data were taken from onerepresentative experiment.

RNA Isolation, cDNA Synthesis and Real Time PCR

Total cellular RNA was isolated from EPDC using the RNeasy Kit (QiagenGmbH, Hilden, Germany) according to manufacturer's instructionsincluding the DNase digestion step. 5 μg of total RNA were reversetranscribed in a 50 μl reaction containing 40 U RNaseOUT (Invitrogen,Frederick, Md., USA), 150 ng of random hexamer primers (Roche Manheim,Germany), 10 mM dNTPs (Invitrogen), and 200 U of Superscript II(Invitrogen). The cDNA sample (0.2 μl) was subjected to qPCR usingprimer sets specific for the various genes or control genes at anoptimized oligonucleotide concentration of 0.4 μW. Forward (F) andreverse (R) specific primer sequences were:

UPA-F: TTTGCGGCCATCTACAGGAG (SEQ ID NO: 18) UPA-R: AGTTAAGCCTTGAGCGACCCA(SEQ ID NO: 19) KDR-F: TGTGGGTTTGCCTAGTGTTTCT (SEQ ID NO: 20) KDR-R:CACTCAGTCACCTCCACCCTT (SEQ ID NO: 21) eNOS-F: CTCATGGGCACGGTGATG(SEQ ID NO: 22) eNOS-R: ACCACGTCATACTCATCCATACAC (SEQ ID NO: 23) MMP2-F:TGATCTTGACCAGAATACCATCGA (SEQ ID NO: 24) MMP2-R: GGCTTGCGAGGGAAGAAGTT(SEQ ID NO: 25)

Reactions were performed in a total volume of 20 μl using the FastStartDNA Master^(Plus) SYBR Green I kit according to the manufacturer'sinstructions (Roche). Amplification cycles were as following: 10 min at95° C. (hot start PCR), followed by 40 cycles of 10 sec at 95° C., 10sec at 62° C. and 20 sec at 72° C. (product amplification). At the endof amplification cycles, melting temperature analysis was performed byslow increase in temperature (0.1° C./sec) up to 95° C. Amplification,data acquisition and analysis were performed using a Light Cyclerinstrument and the LightCycler 3.5.2 software (Roche). The thresholdcycle (Ct) for each gene was normalized to that of GAPDH. The valuesgiven refer to the number of transcript copies for a given gene for 10⁶GAPDH transcript copies.

Peptides, Antibodies and Inhibitors

A recombinant human soluble form of CD146 (rh-sCD146) and its FITCconjugated version were prepared. This peptide corresponds to anN-terminal c-myc epitope tagged extracellular domain of human CD146(EQKLISEEDL (SEQ ID NO: 26)). The tag was used for specific tracking ofthe exogenous recombinant protein and for control immunodepletionexperiments. The corresponding c-myc peptide (Abcam) was used as acontrol. Fc-CD146 was generated by fusing the Fc part of human IgG1 withthe extracellular part of human CD146. Anti-KDR (Sigma), anti uPa(American diagnostic inc.), anti-MMP-2 (Calbiochem), anti e-NOS (SantaCruz Biotechnology), anti-CD146 (clone S-Endo-1; Biocytex), anti-CD31(B&D), anti CD45 (B&D), anti CD33 (B&D), and anti-CD117 (B&D) antibodieswere used at 1/500 dilution. Anti-mouse antibodies used in this studyare: anti-CD45, anti-CD34, anti-asma, anti-MOMA2 (Dako Inc.; Glostrup;Denmark), Alexa fluor 488 anti-CD31 and Alexa fluor 647 anti-CD117(Biolegend), anti-CD33 (Santa Cruz) and anti-CD146.

Anti-rat antibodies used in this study are: anti-CD117 (Neuromics), andanti-CD146. An anti-VEGFR2 blocking antibody was used (r212; AcrisAntibodies GmbH, Herford; Germany).

An immunoassay was used to determine VEGF concentration in culturemedium. Experiments were performed as described by the manufacturer(Invitrogen).

Statistical Analysis

Data were expressed as mean±SEM of the indicated number of experiments.Statistical analysis was performed with the Prism software (GraphPadSoftware Inc., San Diego, USA). Significant differences were determinedusing non parametric Mann Whitney test. A P value <0.05 was consideredas significant.

Results

Recombinant Human Soluble CD146 Displays Chemotactic Activity onEndothelial Cells in vivo and in vitro

Inventors investigated the chemotactic properties of rh-sCD146 onendothelial cells by implanting in non immunocompromised mice athree-dimensional matrigel plug containing rh-sCD146 (0.1 μg/μl). Thec-myc peptide (0.1 μg/μl ) was used as a control molecule sincerh-sCD146 is myc-tagged (see Materials and Methods). Results showedthat, after 14 days, rh-sCD146 Matrigel plugs contained about 100 timesmore cells than the control Matrigel plugs. These cells were able toorganize into vascular-like structures and most of them were positivelystained for CD31, illustrating that they were from endothelial origin(FIG. 1A).

To examine the different cell types present in matrigel plugs filledwith rh-sCD146, stainings were performed with CD31, CD45, CD34, α-SMA,CD117 and MOMA-2. Results presented in FIG. 1B show that hematopoieticcells (CD45 positive), monocytes/macrophages (MOMA-2 positive), smoothmuscle cells and/or pericytes (α-SMA positive) and endothelial cells(CD31 positive) could be recruited by rh-sCD146. Among the cellsintegrated in vascular-like structures, inventors observed CD34 positivecells (a marker of hematopoietic stem cells and of progenitor/ matureendothelial cells) and immature cells stained by the undifferentiationmarker CD117. To better characterize these cells, co-stainings wereperformed (FIG. 1B). Results show that CD31 positive cells implicated invascular-like structures were also CD146 positive. Interestingly, about10-15% of CD31 positive or CD146 positive cells present in vascular-likestructures were co-stained with the undifferentiation marker CD117 (FIG.1B). Finally, double labelling CD117+/CD33− and CD117+/CD45− showed thatthese undifferentiated cells were not of myeloid or hematopoieticorigin.

Inventors performed the same type of matrigel plugs experiments in nudemice injected with human EPC (FIG. 1B). Matrigel plugs implanted in nudemice and containing rh-sCD146 (1 μg/μl) were able to mobilize a largenumber of cells compared to control plugs, as already observed in normalmice (see above). Part of these cells were human EPC, as demonstrated bythe positive labelling with an anti-human CD31 antibody, whereas nohuman EPC was observed in control plugs in the same animals.Interestingly, EPC also participated in the elaboration of structuredvessels (FIG. 1B).

The chemotactic activity of rh-sCD146 on EPC was confirmed in vitro(FIG. 1C). The chemotactic activity of rh-sCD146 was increased from 0 to50 ng/ml and then remained in plateau up to 400 ng/ml. The chemotacticeffect observed with 50 ng/ml rh-sCD146 was similar to that observedwith 20 ng/ml VEGF. No chemotactic activity could be detected in samplestreated with either the c-myc peptide or buffer solution afterimmunodepletion of rh-sCD146. Altogether, these results demonstrate thatrh-sCD146 was able to mobilize both mature and immature endogenousendothelial cells and exogenously administrated EPC. This is animportant property of the molecule since EPC constitute major actors inangiogenesis and vasculogenesis.

Recombinant Human Soluble CD146 Increases Angiogenic Capacity ofEndothelial Progenitor Cells (EPC) in vitro

Inventors examined the influence of rh-sCD146 on the functionalproperties of EPC. For this purpose, they evaluated the effects ofdifferent concentrations of rh-sCD146 on EPC tube formation, migrationand proliferation and compared these effects with those of theangiogenic cytokine VEGF. The formation of capillary tubes was evaluatedin a model of Matrigel plug, a laminin-based gel that mimics the cellmicroenvironment and enables tri-dimensional cell organization (FIG.2A). When EPC were seeded on matrigel plugs, spontaneous formation ofendothelial tubes occurred, the tubes forming in turn a capillarynetwork. The addition of rh-sCD146 improved the development of thisnetwork as illustrated by the increase in tube number (FIG. 2A) andlength (data not shown). This effect was dose-dependent between 25 and100 ng/ml rh-sCD146. The effect observed with 50 ng/ml rh-sCD146 wassimilar to that observed with 20 ng/ml VEGF. No effect was observed whencells were treated with the control c-myc peptide or withimmuno-depleted rh-sCD146. The effect of rh-sCD146 was also evaluated onEPC proliferation (FIG. 2B) and migration (FIG. 2C). In both cases, theeffect of rh-sCD146 was specific of the molecule (no effect of thebuffer after immuno-depletion of rh-sCD 146) and dose-dependent. Inthese experiments, the effect of 50 ng/ml rh-sCD146 was also similar tothat observed with 20 ng/ml VEGF.

Thus, in addition to recruiting EPC, rh-sCD146 appeared to be able toactivate these cells by increasing their angiogenic activity. EPCproliferation, migration and capacity to organize into vascular-likestructures in Matrigel plugs were increased at an extent very similar tothat observed with VEGF.

Since the pioneering work of Folkman and colleagues in 1971, thetherapeutic potential of several angiogenic growth factors has beenextensively investigated.

Among them, VEGF has been repeatedly shown to increase angiogenesis andnumerous therapeutic approaches have been tested based on the injectionof either VEGF peptides or plasmid DNA encoding VEGF (Nomi M, Miyake H,Sugita Y, Fujisawa M, Soker S. Role of growth factors and endothelialcells in therapeutic angiogenesis and tissue engineering. Curr Stem CellRes Ther. 2006; 1:333-43).

bFGF has also been shown to increase collateral arteriolar growth andexperiments have suggested an interdependence between VEGF and bFGF(Stavri G T, Zachary I C, Baskerville Pa., Martin J F, Erusalimsky J D.Basic fibroblast growth factor upregulates the expression of vascularendothelial growth factor in vascular smooth muscle cells. Synergisticinteraction with hypoxia. Circulation. 1995; 92 (1) :11-4).

Angiopoietin-1, which mediates the recruitment of vascular smooth musclecells by developing vessels, erythropoietin (EPO) and granulocyte-colonystimulating factor (G-CSF) also appear to be involved in the collateralformation of vessels after ischemia in infarcted myocardium (VanderveldeS, van Luyn M J, Tio R A, Harmsen M C. Signaling factors in stemcell-mediated repair of infarcted myocardium. J Mol Cell Cardiol. 2005;39(2):363-76). Finally, the endothelial nitric oxide synthase e-NOS wasshown to display a potent angiogenic effect in ischemic tissues (Duda DG, Fukumura D, Jain R K., Role of eNOS in neovascularization: NO forendothelial progenitor cells. Trends Mol Med. 2004; 10:143-5).

The soluble form of CD 146 now appears as a new very relevant angiogenicgrowth factor, as herein demonstrated by inventors. Inventors' in vitroexperiments indeed show that the effects obtained with 50 ng/mlrh-sCD146 were similar to that observed with 20 ng/ml VEGF (FIG. 2).

As rh-sCD146 and VEGF effects were very similar, inventors testedwhether their effects were additive, synergistic or not. To this end,the same experiments were performed with the addition of both factors,rh-sCD146 50 ng/ml and VEGF 20 ng/ml (FIG. 5). Results show that effectsof both molecules are additive on EPC proliferation (FIG. 5A), migration(FIG. 5B) and ability to form capillary-like structures in matrigel(FIG. 5C). To go further in the mechanism, they performed additionalexperiments of capillary tubes formation in matrigel in the presence ofanti-VEGFR2 antibodies. These antibodies were either incubated with thecells all along the treatment with VEGF and/or rh-sCD146 to totallyblock VEGFR2, or preincubated with the cells before antibodies washingand further treatment with rh-sCD146 plus VEGF. This last conditionallows blocking VEGFR2 present on the membrane before stimulation, butnot VEGFR2 eventually induced by rh-sCD146.

Results (FIG. 5C) show that anti-VEGFR2 antibodies 1/had no effect incontrol condition, 2/totally blocked the VEGF effect, and 3/partiallyblocked the effect of rh-sCD146. When rh-sCD146 and VEGF were added inthe presence of antibodies, the number of capillary-like structures wasdecreased as compared to the condition without antibodies, and thenumber of tubes was similar to that observed with rh-sCD146 in thepresence of anti-VEGFR2 antibodies. Finally, when cells were pre-treatedwith the anti-VEGFR2 antibodies before washing of the antibodies andfurther stimulation with rh-sCD146 and VEGF, the number ofcapillary-like structures was significantly higher than in the previouscondition, suggesting the induction of new VEGFR2 by rh-sCD146 at thecell surface. Altogether, these experiments indicate that rh-sCD146response involves in majority a sCD146-specific pathway but also, in aminor part, the VEGF signalling pathway, by inducing new VEGFR2 at thecell surface.

Experiments were also performed to test whether VEGF secretion wasmodified by rh-sCD146 treatment. EPC treated for 24hours with 50 ng/mlrh-sCD146 exhibited a statistically significant increase in VEGFsecretion as compared to non-treated EPC (71.8+/−6.1 versus 54.8+/−3.2pg/ml, n=6; p<0.05).

Recombinant Human CD146 Induces Transcription of Pro-angiogenic Genes inEndothelial Progenitor Cells

Inventors hypothesized that the functional effects of rh-sCD146 observedon EPC could depend in part on gene transcription. To test thishypothesis, they monitored alterations in gene expression upon treatmentof EPC with rh-sCD146 using oligo-arrays specific for angiogenic genes.Among the 113 probed genes (see Methods), some were up-regulated, otherswere down-regulated or not modified. Among the up-regulated genes, theychoose four genes that were reproducibly up-regulated at least 5-fold inEPC treated for 3h with 50 ng/ml rh-sCD146. They included eNOS, the VEGFreceptor 2 (KDR), the matrix metallopeptidase MMP-2 and the plasminogenactivator urokinase (PLAU/u-Pa) (FIG. 3). Alterations in expression ofthese genes upon treatment of EPC with 50 ng/ml rh-sCD146 were confirmedby qPCR and Western-blot analysis. qPCR experiments revealed that mRNAsfor all four genes were effectively significantly increased 3 hoursafter treatment with 50 ng/ml rh-sCD146 (FIG. 3A). At the protein level,expression of eNOS and u-Pa increased significantly 1 h after treatmentwhile the increase in KDR and MMP-2 was observed 3 h post-treatment(FIGS. 3B and 3C). Increased protein expression was sustained for 24hours.

Thus, one of the main effects of rh-sCD146 was to increase thetranscription and translation of several pro-angiogenic proteins.Proteins that are up-regulated by rh-sCD146 in this study appear to beof particular importance during angiogenesis.

The activity of KDR in particular is dramatically increased duringvasculogenesis or during tumor angiogenesis. It acts on endothelialcells by inducing the expression of several proteins such as uPA, uPARand some MMPs. Two other proteins induced by rh-sCD146 in our study areu-PA and MMP-2. They belong to proteolytic complexes which promote thedegradation of the basal membrane and of the extracellular matrix duringmigration and cellular proliferation. They are involved both inphysiological and tumoral angiogenesis. Of interest, the activity ofCD146 often appears to be coupled to that of MMP-2. Indeed, it has beenshown that the treatment of melanoma by anti-MUC18 antibodies decreasedthe capacity of HUVEC to colonize Matrigel plugs in vitro and that thiswas associated with a decrease in the collagenase activity of MMP-2.

eNOS, another rh-sCD146-induced protein, also appears to play a key rolein angiogenesis. The role of eNOS in the mobilization of stem cellsappears to be essential. Pretreatment of bone marrow mononuclear cellsderived from patients with ischemic cardiomyopathy with the eNOSsynthase transcription enhancer AVE9488 is able to restore the capacityof these progenitor cells to induce neovascularisation.

Local Injection of Recombinant Human Soluble CD146 IncreasesNeovascularisation in a Rat Ischemic Hind Limb Model

In light of the in vitro and in vivo properties of rh-sCD146, inventorstested its potential therapeutic effects in an in vivo model of rathindlimb ischemia. Results presented in FIG. 4A showed that, after 5days of treatment of the ischemic hindlimb with 10 μg rh-sCD146/day, thelevel of auto-amputation of the animals was significantly decreased 5days after initiation of ischemia, as compared to control animalstreated with the c-myc peptide. In contrast, it was not significantlydifferent between treatment groups 10 or 20 days post initiation ofischemia. Laser-doppler tissue imaging showed that obstruction of theleft common femoral artery decreased blood perfusion by about 90% atday 1. Treatment with rh-sCD146 significantly increased the bloodperfusion rate at day 5 as compared to the control group but no furthersignificant modification in blood flow was detectable between the twogroups at days 10 and 20. When animals were treated with the same doseof rh-sCD146 (10 μg/day), but for a longer period of time (12 days), theauto-amputation level was now significantly decreased at day 5, 10 and20, as compared to control rats. In these conditions, the bloodperfusion rate was also significantly increased from day 5 to day 20,reaching about 60% of the blood perfusion rate in the control leg of thesame animals at day 20 (FIG. 4A). Histochemical examination of musclesections after 20 days showed inflammation, calcification, fibrosisareas and numerous necrosed muscular fibers in ischemic hindlimbs thatwere not treated by rh-sCD146 (FIG. 4B). In contrast, in ischemichindlimbs treated with rh-sCD 146 for 12 days, almost no fibrosis wasobserved, inflammation and necrosed muscular fibers were highly reduced(FIG. 4B and FIG. 4C). Examination of capillaries showed that theirnumber was significantly increased, as compared to control ischemiclimbs, and muscle aspect was greatly improved with a majority of intactmuscular fibers (FIG. 4B and FIG. 4C). Interestingly and advantageously,inventors also observed a trophic effect of rh-sCD146 on healing ofamputated limbs (data not shown).

As CD117/CD146 positive endothelial precursor cells participating invascular-like structures were observed in vivo in matrigel plugscontaining rh-sCD146 (see FIG. 1B), inventors tested whether such cellscould also be detected in rat muscles after ischemia. To this end,inventors analyzed muscles of rats with hind limb ischemia, treated ornot with rh-sCD146, two days after the beginning of the treatment inorder to detect early events. Results show that CD117/CD146 positivecells could be detected in rh-sCD146 treated animals whereas these cellswere not found in control rats (FIG. 4D).

CONCLUSION

Experiments of matrigel plugs in vivo showed that sCD146 displayedchemotactic activity on different cell types, including endothelialcells, as attested by their insertion into vascular-like structures andtheir positive staining for endothelial marker as CD34, CD146 or CD31(double staining of these cells show that they are CD33 and CD45negative, indicating that they are not of myeloid or hematopoieticorigin), and hematopoietic cells such as monocytes, smooth muscle cellsand/or pericytes. These experiments further showed that sCD146 was ableto recruit exogenously injected late endothelial progenitor cells (EPC),also herein identified as EPDC.

Recruited endothelial cells participated in formation of vascular-likestructures. In vitro, sCD146 enhanced angiogenic properties of EPC, withan increased cell migration, proliferation and capacity to establishcapillary-like structures.

Up to now, the receptor of soluble CD146 is still unknown. The membraneCD146 is not this receptor since no homophilic interactions between bothmolecules has been evidenced.

Observed effects were, in particular, additive with those of VEGF.sCD146 enhanced VEGFR2 expression and VEGF secretion.

Consistent with a pro-angiogenic role, gene expression profiling ofsCD146-stimulated EPC revealed, in particular, an up-regulation of eNOS,uPa, MMP2 and VEGFR2. Silencing membrane-bound CD146 inhibited theseresponses.

The potential therapeutic interest of sCD146 was tested in a model ofhindlimb ischemia. The present invention demonstrates that localinjections of sCD146 significantly reduced auto-amputation, tissuenecrosis, fibrosis, inflammation, and increased blood flow. It is hereinestablished that sCD146 displays chemotactic and angiogenic propertiesand promotes efficient neovascularisation in a model of limb ischemia.Recombinant human sCD146 thus support novel strategies for therapeuticangiogenesis in ischemic diseases and disorders.

The complete mechanism governing the favourable effects of sCD146 isunknown and remains to be established but several pathways could beinvolved. sCD146 could act on local endothelial resident cells and/ormonocyte infiltration since inventors evidenced a chemotactic effect onmonocytes in matrigel plugs in vivo (Bardin N, Blot-Chabaud M, DespoixN, et al. CD146 and its soluble form regulate monocyte transendothelialmigration. Arterioscler. Thromb Vasc Biol. 2009; 29: 746-53).Alternatively, or additionally, sCD146 may play a role in vasculogenesisby recruiting endothelial progenitor cells to area ofneovascularisation. In agreement with this last hypothesis, cellspresenting characteristics of late endothelial progenitors wererecruited in matrigel plugs and organized as vascular-like structures.In addition, immature endothelial cells could be observed in musclesections of animals after two days of treatment with sCD146.

Example 2 Study of the Healing Activity of an Active Principle on theCutaneous Healing Kinetics on Living Human Skin Explants

The aim of the study was to demonstrate the activity of sCD146 on thehealing kinetics of epidermal and dermal lesions induced by UVBirradiation on living skin explants. This activity was evaluated byobservation of the general morphology, and by specific immunolabels forfibronectin and integrin β4.

Operating Method

Preparation of the Explants

Thirty explants from an abdominoplasty of a 42-year old woman (P718AB42)were prepared and kept alive in BIO-EC's Explant Medium (BEM).

The explants were divided into 2 lots of 9 explants and 2 lots of 6explants in a 12-well culture dish each containing 1 mL BEM as follows:

Lot Nature Number of explants N Normal untreated skin 9 B Burneduntreated skin 9 BP1 Burned skin + P1 (topical 6 application) BP2 Burnedskin + P2 6 (incorporated in the culture medium)Epidermal and Dermal Lesions

Epidermal and dermal lesions were created by UVB irradiation of 10J/cm², delivered by a Vilber Lourmat UV simulator with a RMX3W controlunit. The burning was limited to the center of the explant over a 4 mmdiameter area.

2. Application of the Products

sCD146 was tested at a concentration of 7.5 μg per explant. It wasapplied topically (30 μL on a filter paper disk applied onto theexplant) (P1) and 19 μL incorporated in 1 mL BEM (P2). The P1 and P2products were applied topically and incorporated into the BEM on D0, D2,D5, D6 and D8. The culture media were refreshed at the same time.

3. Samples

On D0, the 3 explants of lot N and B were sampled at the end ofirradiation. They were cut in half: one half was fixed in ordinaryBouin's solution and the other half was stored at −80° C. At time D4 andD11, 3 explants from each lot were sampled and treated in the same way.

4. Histology

After 48 hours of fixation in the Bouin's solution, the samples weredehydrated and impregnated in paraffin by means of a Leica 1020 tissueprocessor. They were embedded according to operating procedure MO-H-153by means of a Leica EG 1160 embedding center. Sections of 5 μm were madeaccording to operating procedure MO-H-173 by means of a Leica RM 2125Minot mictrotome and affixed to Superfrost® histologically-silanizedglass slides. Frozen samples were sectioned at 7 μm in a Leica CM3050cryostat. The sections were affixed onto histologically-silanized glassslides for the immunological labeling. The microscopic observations weremade by light microscopy, by means of a Leica Orthoplan microscope, witha X25 objective. The photographs were taken with a Sony DXC 390P tri CCDcamera and stored by Leica 1M1000 data archiving software.

4.1 General Morphology

The general morphology was observed on paraffin sections after stainingwith Masson's trichrome, Goldner's variant, according to operatingprocedure MO-H-157.

4.2 Fibronectin Immunolabeling

Fibronectin was labelled on frozen sections, with a mouseanti-fibronectin monoclonal antibody, clone TV-1, from Chemicon (ref MAB88904), at 1/50^(th) for 1 h at ambient temperature with abiotin/streptavidin amplifier system, revealed by FITC, with the nucleicounterstained with propidium iodide. This labeling was done on theexplants sampled at T0 and D4.

4.3 Immunolabeling of Integrin β4

Integrin β4 was labeled on frozen sections with a mouse anti-integrin β4monoclonal antibody, clone 3E1 from Chemicon (ref MAB 1964), at1/600^(th) for 1 hour 30 minutes at ambient temperature, with abiotin/streptavidin amplifier system, revealed by FITC, with the nucleicounterstained with propidium iodide. This labeling was done on theexplants taken at T0 and D11.

Activity Criteria Examined

The healing activity was examined on the edges and on the lesion inducedby UVB.

Glossary of Histological Terms Used:

Spongiosis: intercellular oedema without breaking the desmosomal bonds.

Acantholysis: intercellular oedema with breaking of the desmosomalbonds.

Pycnotic nuclei: nuclear degeneration leading to cell necrosis.

Cellular oedema: swelling of the cell

Epidermal acanthosis: increase in the thickness of the epidermis due toan increase in the number of cell layers or an increase in the size ofthe keratinocytes.

Parakeratosis: keratinization of the stratum granulosum, the last livingepidermal layer.

Results

General Morphology

On D0:

Unburned Lot (N0)

The stratum corneum is thick, moderately lamellar, moderatelykeratinized on the surface and at its base. The epidermis has 4 to 5cell layers with good morphology. The dermal-epidermal junctiontopography is moderate. The papillary dermis has fairly thick collagenfibres forming a fairly dense network. It is well cellularized.

Burned Lot (B0)

The stratum corneum is thick, fairly lamellar, moderately keratinized onthe surface and at its base. The epidermis has 4 to 5 cell layers withgood morphology. The dermal-epidermal junction topography is moderate.The papillary dermis has fairly thick collagen fibres forming a fairlydense network. It is well cellularized.

On D4:

Unburned Lot (NJ4)

The stratum corneum is thick, slightly lamellar, slightly keratinized onthe surface and at its base. The epidermis has 4 to 5 cell layers withgood morphology. The dermal-epidermal junction topography is moderate.The papillary dermis has fairly thick collagen fibres forming a fairlydense network. It is well cellularized.

Untreated Burned Lot (BJ4)

On the unburned zone, the stratum corneum is thick, moderately lamellar,slightly keratinized on the surface and at its base. The epidermis has 4to 5 cell layers with good morphology. The dermal-epidermal junctiontopography is moderate. The papillary dermis has fairly thick collagenfibres forming a fairly dense network. It is well cellularized.

On the lesion, the alterations are very marked, with rather numerouskeratinocytes with clearly pycnotic nuclei and perinuclear oedema. Thekeratinocytes have good morphology and are present in moderate numbers,primarily basally.

On the edges of the lesion, the keratinocytes have good morphology, havea fairly strong presence and are moderately stratified. The keratinocytegrowth bud is moderate, somewhat thick, with a moderate progression ofneo-keratinocytes under the altered structures.

Burned+product P1 Lot (BP1J4)

On the unburned zone, the stratum corneum is thick, slightly lamellar,moderately keratinized on the surface and at its base. The epidermis has4 to 5 cell layers with good morphology. The dermal-epidermal junctiontopography is fairly marked. The papillary dermis has fairly thickcollagen fibres forming a fairly dense network. It is well cellularized.

On the lesion, the alterations are marked, with fairly numerous,moderately oedematous keratinocytes with pycnotic nuclei and perinuclearoedema. The keratinocytes with a good morphology are moderate in number,primarily basally.

On the edges of the lesion, the keratinocytes have good morphology andare moderate in number, fairly regular and not very stratified. Thekeratinocyte growth bud is small and thin, with a poor progression ofneo-keratinocytes under the altered structures.

Burned+Product P2 Lot (BP2J4)

On the unburned zone, the stratum corneum is thick, slightly lamellar,moderately keratinized on the surface with slight parakeratosis. Theepidermis has 4 to 5 cell layers with good morphology. Thedermal-epidermal junction topography is moderate. The papillary dermishas fairly thick collagen fibres forming a network that is not verydense. It is well cellularized.

On the lesion, the alterations are fairly moderate, with a moderatenumber of keratinocytes with pycnotic nuclei and perinuclear oedema.Keratinocytes with good morphology are fairly numerous basally andsuprabasally with a few slightly stratified neo-keratinocyte zones.

On the edges of the lesion, keratinocytes with good morphology areclearly present and not very stratified. The keratinocyte growth bud issmall and thin, with a poor progression of neo-keratinocytes under thealtered structures.

On D11:

Unburned Lot (NJ11)

The stratum corneum is very thick, slightly lamellar, slightlykeratinized on the surface, with very marked parakeratosis. Theepidermis has 5 to 6 cell layers with moderately altered morphology.There is marked basal spongiosis. The dermal-epidermal junctiontopography is moderate. The papillary dermis has fairly thick collagenfibres forming a fairly dense network. It is well cellularized.

Burned and Untreated Lot (BJ11)

On the unburned zone, the stratum corneum is thick, moderately lamellar,moderately keratinized on the surface with advanced parakeratosis. Theepidermis has 4 to 5 cell layers with a moderately altered morphology.There is marked basal spongiosis. The DEJ topography is moderate. Thepapillary dermis has somewhat thick collagen fibres forming a fairlydense network. It is well cellularized.

On the lesion, the alterations are very marked, with numerouskeratinocytes with clearly pycnotic nuclei and perinuclear oedema.Keratinocytes with good morphology are scarce basally andnon-stratified.

On the edges of the lesion, keratinocytes with good morphology areclearly present and fairly well stratified in 2 or 3 cell layers. Thekeratinocyte growth bud is very clear, moderately thick with a verymarked progression of neo-keratinocytes under the altered structures(approximately 2.5 microscopic fields).

Burned+Product P1 Lot (BP1J11)

On the unburned zone, the stratum corneum is thick, moderately lamellar,slightly keratinized on the surface with very marked parakeratosis. Theepidermis has 3 to 4 cell layers with moderately altered morphology.These alterations are characterized by the presence of a moderate numberof moderately oedematous cells with pycnotic nuclei and perinuclearoedema in the upper epidermal layers. There is moderate basalspongiosis. The dermal-epidermal junction topography is moderate. Thepapillary dermis has fairly thick collagen fibres forming a network thatis not very dense. It is well cellularized.

On the lesion, the alterations are marked, with very numerouskeratinocytes with pycnotic nuclei and perinuclear oedema. Keratinocyteswith good morphology are very scarce.

On the edges of the lesion, keratinocytes with good morphology arescarce, very irregular and not well-stratified. The keratinocyte growthbud is small and thin, poorly structured, with a poor progression ofneo-keratinocytes under the altered structures.

Burned+Product P2 Lot (BP2J4)

On the unburned zone, the stratum corneum is thick, moderately lamellar,slightly keratinized on the surface, with very marked parakeratosis. Theepidermis has 3 to 4 cell layers with clearly altered morphology. Thesealterations are characterized by the presence of numerous, clearlyoedematous cells with pycnotic nuclei and perinuclear oedema in theupper cell layers. There is marked basal and suprabasal spongiosis. Thedermal-epidermal junction topography is moderate. The papillary dermishas fairly thick collagen fibres forming a network that is not verydense. It is well cellularized.

On the lesion, the alterations are very marked, with numerouskeratinocytes with pycnotic nuclei and perinuclear oedema.Neo-keratinocytes with good morphology are moderate in number basally,and slightly stratified.

On the edges of the lesion, keratinocytes with good morphology areclearly present and fairly well stratified. The keratinocyte growth budis fairly clear and thin, slightly stratified over 2 to 3 cell layers,with a clear progression of neo-keratinocytes under the alteredstructures (approximately 2 microscope fields).

Fibronectin

No labeling is observed after replacing the primary antibody orsecondary antibody by PBS, which shows the specificity of the labelingobserved.

On D0:

Unburned Lot (N0)

The labeling is clear throughout the papillary dermis. It is dense andclearly filamentous.

Burned Lot (B0)

The labeling is clear throughout the papillary dermis. It is dense andclearly filamentous.

On D4:

Unburned Lot (NJ)

The labeling is fairly clear throughout the papillary dermis. It isdense and moderately filamentous.

Burned and Untreated Lot (BJ4)

On the unburned zone, the labeling is fairly clear throughout thepapillary dermis. It is dense and moderately filamentous.

On the lesion, the labeling is fairly clear throughout the papillarydermis. It is fairly dense and clearly filamentous.

Burned+Product P1 Lot (BP1J4)

On the unburned zone, the labeling is fairly clear throughout thepapillary dermis. It is dense and moderately filamentous.

On the lesion, the labeling is clear throughout the papillary dermis. Itis dense and very clearly filamentous.

Burned+Product P2 lot (BP2J4)

On the unburned zone, the labeling is fairly clear throughout thepapillary dermis. It is dense and moderately filamentous.

On the lesion, the labeling is clear throughout the papillary dermis. Itis fairly dense and clearly filamentous.

Integrin β4

No labeling was observed after replacing the primary or secondaryantibody by PBS, which shows the specificity of the labeling observed.

On D0:

Unburned Lot (N0)

The labeling is clear and regular. It is moderate laterally on the basalkeratinocytes.

Burned Lot (B0)

The labeling is clear and regular. It is moderate laterally on the basalkeratinocytes.

On D11:

Unburned Lot (NJ11):

The labeling is fairly clear and fairly regular. It is moderatelaterally on the basal keratinocytes.

Burned and Untreated lot (BJ11):

On the unburned zone, the labeling is fairly clear and fairly regular.It is moderate laterally on the basal keratinocytes.

On the lesion, the labeling is moderate and irregular. It is verymoderate laterally on the basal keratinocytes.

Burned+Product P1 Lot (BP1J11):

On the unburned zone, the labeling is fairly clear and regular. It ismoderate laterally on the basal keratinocytes.

On the lesion, the labeling is fairly clear and fairly regular. It isvery moderate laterally on the basal keratinocytes.

Burned+Product P2 Lot (BP2J11):

On the unburned zone, the labeling is fairly clear and fairly regular.It is moderate laterally on the basal keratinocytes.

On the lesion, the labeling is very clear and fairly regular. It ismoderate laterally on the basal keratinocytes.

Discussion

General Morphology

On D 4 On D 11 Neo-keratino- Neo-keratino- cytes on the Intensity of thecytes on the Intensity of the Lot lesion growth bud lesion growth bud B− ++ − ++++ BP1 − + − + BP2 + + ++ +++ Neo-keratinocytes: Noneo-keratinocytes: − Few neo-keratinocytes: + Moderate number ofneo-keratinocytes: ++ Numerous neo-keratinocytes: +++ Intensity of thegrowth bud: Negative: − Low: + Moderate: ++ Marked: +++ Very marked:++++

On D4:

Compared to the Burned and Untreated Lot:

Treatment with product sCD146 applied topically (P1) did not induce anyepidermal restructuring activity either on the edges of the lesion or onthe lesion itself. Treatment with sCD146 incorporated into the BEM (P2)induces a weak epidermal restructuring activity with the presence of afew basal neo-keratinocytes on the lesion.

At this time, mild epidermal intolerance reactions appeared, stronger onthe lot treated with sCD146 applied topically.

On D11:

Compared with the Burned and Untreated Lot:

Treatment with sCD146 applied topically (P1) does not induce epidermalrestructuring activity either on the edges of the lesion or on thelesion itself.

Treatment with sCD146 incorporated into the BEM (P2) induces a weakepidermal restructuring activity, characterized by the presence on thelesion of a moderate number of neo-keratinocytes and by the presence onthe edges of a fairly marked epidermal growth bud.

At this time, marked epidermal intolerance reactions appear, very strongin the lot treated with CD146 applied topically and more moderate withproduct CD146 incorporated into the BEM.

Fibronectin

On D 4 Lot Unburned Lesion B ++ +++ BP1 ++ ++++ BP2 ++ +++ Expression offibronectin: Negative: − Low: + Moderate: ++ Marked: +++ Very marked:++++

On D0:

The fibronectin is clear in the papillary dermis. It is dense andclearly filamentous.

On D4:

On the unburned zones, the expression of fibronectin does not change.

On the injured areas, with sCD146 applied topically (P1), theoverexpression of fibronectin is marked, showing a clearly morefilamentous network, promoting the migration of fibroblasts of thepapillary dermis. This overexpression is lesser with sCD146 incorporatedinto the survival medium (P2).

Integrin β4:

On D 11 Lot Unburned Lesion B +++ ++ BP1 +++ +++ BP2 +++ ++++ Expressionof integrin β4: Negative: − Low: + Moderate: ++ Marked: +++ Very marked:++++

On D0:

The expression of integrin β4 is clear and regular. It is moderatelaterally on the basal keratinocytes.

On D11:

On the unburned and untreated lot, the expression of integrin β4 isfairly clear and fairly regular. It is moderate laterally on the basalkeratinocytes.

On the Treated Lots

On the unburned zones, the expression of integrin β4 does not changemuch, regardless of the treatment, with regard to the untreated control.

On the injured zones, with sCD146 applied topically (P1); integrin β4 ismoderately overexpressed with regard to the untreated control. It isclearly overexpressed with sCD146 incorporated into the survival medium.

CONCLUSION

General Morphology:

sCD146 incorporated into the BEM survival medium for 11 days induces themost marked epidermal restructuring activity observed, both on the edgesof the lesion and on the lesion itself, characterized by the presence ofa moderate number of slightly stratified neo-keratinocytes in the basalposition. However, this activity is attenuated by rather markedepidermal intolerance reactions.

Fibronectin:

Fibronectin is an early dermal healing marker. Its overexpression, after4 days of survival, indicates an improvement in its network in thepapillary dermis, promoting the migration of fibroblasts, which willultimately colonize the altered zone.

On the burned and untreated lot, the expression of fibronectin isincreased on the lesion, which is a normal activity of dermal healing.The most marked overexpression of fibronectin is observed with sCD146applied topically.

Integrin β4:

Integrin β4 is involved in anchoring keratinocytes onto the basementmembrane at the hemidesmosomes. Its restructuring or maintenance is afavourable index for showing epidermal healing activity. sCD146incorporated into the medium for 11 days induces the clearest activityon integrin β4.

The Above Detailed Experiments Demonstrate That:

-   -   sCD146 incorporated into the survival medium has the best        activity with regard to keratinocyte stimulation and integrin β4        expression (as confirmed by data appearing on FIG. 8).    -   sCD146 applied topically has the best activity on dermal        restructuring.

The invention claimed is:
 1. A composition comprising human solubleCD146 protein consisting of SEQ ID NO: 7, wherein said human solubleCD146 protein is acetylated, methylated, phosphorylated or fused toanother polypeptide and a pharmaceutically acceptable carrier.
 2. Thecomposition according to claim 1, further comprising an angiogenicfactor selected from the group consisting of vascular endothelial growthfactor (VEGF), stromal-cell-derived-factor-1 (SDF-1), basic fibroblastgrowth factors (bFGF), erythropoietin (EPO), granulocytecolony-stimulating factor (G-CSF), granulocyte-macrophage colonystimulating factor (GM-CSF), stem cell factor (SCF), interleukin-8(IL-8) and mixtures thereof.
 3. The composition according to claim 1,further comprising an endothelial progenitor cell (EPC), said cellhaving, optionally, been contacted with said human soluble CD146protein.
 4. A method of treating limb ischemia in a mammal comprisingadministering to the mammal an isolated human soluble CD146 proteinconsisting of SEQ ID NO: 7, said human soluble CD146 protein beingoptionally acetylated, methylated, phosphorylated, glycosylated or fusedto another polypeptide, or a composition comprising said soluble CD146protein and a pharmaceutically acceptable carrier.
 5. An isolated humansoluble CD146 protein consisting of SEQ ID NO: 7, wherein said humansoluble CD146 protein is acetylated, methylated, phosphorylated or fusedto another polypeptide.
 6. The isolated human soluble CD146 protein ofclaim 5, wherein said human soluble CD146 protein is acetylated.
 7. Theisolated human soluble CD146 protein of claim 5, wherein said humansoluble CD146 protein is fused to another polypeptide.
 8. The isolatedhuman soluble CD146 protein of claim 5, wherein said human soluble CD146protein is methylated.
 9. The isolated human soluble CD146 protein ofclaim 5, wherein said human soluble CD146 protein is phosphorylated.